Metrology, standardization and certification in energy sector: manual for graduate students 9786010438965

Citation preview

AL-FARABI KAZAKH NATIONAL UNIVERSITY

METROLOGY, STANDARDIZATION AND CERTIFICATION IN ENERGY SECTOR Manual for graduate students

Almaty «Qazaq University» 2019

UDC 621.3 (075) LBC 31.2 я 73 M 61 Recommended for publication by the Scientific Council of the Faculty of Physics and Technology and RISO of Al-Farabi Kazakh National University (Protocol №3 dated 06.02.2019) Reviewers: Doctor of Technical Sciences, Professor А.В. Ustimenko Doctor of Physical and Mathematical Sciences, Professor M.E. Abishev Authors: A.S. Askarova, S.A. Bolegenova, S.A. Bolegenova, O.A. Lavrischev, V.Yu. Maksimov, A.M. Maksutkhanova, Zh.K. Shortanbayeva

M 61

Metrology, standardization and certification in energy sector: manual for graduate students / A.S. Askarova, S.A. Bolegenova, S.A. Bolegenova [et al.]. – Almaty: Qazaq University, 2019. – 129 p. ISBN 978-601-04-3896-5 The manual reviews the basics of metrology and metrological support: terms, physical quantities, measurement theory basic, measuring and control means, metrological characteristics, measuring and controlling electrical and magnetic quantities. The basics of standardization are outlined: development history, legal and regulatory base, international, regional and national, standardization methods, product quality. Particular attention is paid to the fundamentals of certification and conformity assessment. The manual is intended for students of technical specialties of universities, but may also be useful for undergraduates and PhD doctoral candidates.

UDC 621.3 (075) LBC 31.2 я 73 ISBN 978-601-04-3896-5

© Askarova A.S., Bolegenova S.A., Bolegenova S.A. [et al.], 2019 © Al-Farabi KazNU, 2019

CONTENTS

INTRODUCTION.........................................................................6 SECTION 1 Metrology as the science of measurement Chapter 1. BASIC TERMS AND DEFINITIONS.....................10 1.1. The concept and main problems of metrology....10 1.2. The concept of measurement.............................12 Chapter 2. GENERAL INFORMATION ON MEASUREMENTS....14 2.1. Specific features of the measuring process........14 2.2. Measuring instruments......................................17 2.3. Measurement classification................................18 Chapter 3. MEASURING INSTRUMENTS..............................20 3.1. Weight measurement and control......................20 3.2. Measurement and control of geometrical quantities............................................................21 3.3. Measurement and control of mechanical quantities............................................................23 3.3.1. Methods and means of measurement and control kinematic quantities........................23 3.3.2. Methods and means of measurement and control of dynamic quantities............................25 3.3.3. Methods and means of measurement and control of mechanical properties of substances and materials...............................26 3.4. Measurement and control of thermal quantities............................................................27 3.4.1. Methods and means of temperature measurement and control...................................27

3

4

Metrology, standardization and certification in energy sector 3.4.2. Methods and means of measuring and controlling thermal properties of substances and materials..................30 3.5. Measurement and control of electrical and magnetic quantities............................................................................31 3.6. Measurement of pressure, volume and flow of gases and liquids.................................................................................31 3.6.1. Methods and means for measuring and controlling the flow rate and amount of gases and liquids...................32 3.6.2. Means for measuring and signaling the level of liquid......32 3.7. Measuring instruments for direct conversion and comparison.........................................................................33 Chapter 4. PHYSICAL QUANTITIES AND THEIR VALUES...............36 4.1. Relations between quantities, physical equations..............37 4.2. System of quantities...........................................................38 4.3. Characteristics of the international system of units and definition of basic SI units.................................................41 4.4. Standards of physical units................................................42 4.5. Metrological characteristics of measuring instruments (MI)................................................................44 4.6. Use of MI...........................................................................46 4.7. Normalization of MI errors................................................48 Chapter 5. MEASUREMENT ERRORS.....................................................52 5.1. The concept of measurement error.....................................52 5.2. Object models and measurement errors.............................53 5.3. Classification of measurement errors.................................54 5.4. Random errors....................................................................56 5.4.1. Statistical stability of observations distribution.................56 5.4.2. Examples of random variables distribution.......................57 5.5. Systematic errors................................................................60 5.6. Methods for processing the direct measurements results.................................................................................62 Chapter 6. GENERAL INFORMATION ABOUT ELECTRICAL MEASUREMENTS AND CLASSIFICATION OF MEASURING INSTRUMENTS..............................................67 6.1. Types of electrical measurements......................................67 6.2. Measurement of electrical signal parameters.....................70 6.2.1. Voltage measurement.........................................................70 6.2.2. Purpose and classification of electronic voltmeters...........71 6.2.3. Current measurement.........................................................74 6.2.4. Power measurement...........................................................76 6.2.5. Electrical energy measurement..........................................76 6.2.6. Measurement of electrical circuit parameters....................77 6.2.7. Resistance measurement....................................................78

Contents 6.2.8. Capacitance and inductance measurement.........................78 6.3. Standards, model and working measures...........................79 SECTION 2 Standardization Chapter 1. CONCEPTS AND DEFINITIONS...........................................82 1.1. Purpose of standardization.................................................82 1.2. Principles of standardization..............................................84 1.3. Organization of work on standardization...........................84 1.4. Documents in standardization............................................85 1.5. Types of standards..............................................................89 1.6. International standardization..............................................89 Chapter 2. SYSTEM APPROACH TO ENERGY MANAGEMENT.......99 Chapter 3. STANDARDIZATION AT THE ENTERPRISE...................107 SECTION 3 Basics of certification Chapter 1. BASIC CONCEPTS OF CERTIFICATION..........................112 1.1. History of certification in the Republic of Kazakhstan...................................................................112 1.2. Essence of certification....................................................116 1.3. Certification system..........................................................117 1.4. Certification......................................................................119 Chapter 2. TECHNICAL REGULATION.................................................123 REFERENCES...........................................................................................127

5

INTRODUCTION

Standardization, metrology and certification are instruments for ensuring the quality of products, works and services – an important aspect of various activities of enterprises. Mastering the quality assurance methods is currently one of the main conditions for a supplier to enter the market with competitive products (services), and hence the commercial success. The problem of quality is important for all countries without exception. For example, after the Second World War, Germany and Japan ensured the product quality skillfully applying standardization and metrology, thereby giving the start to renewal of their economies. Currently, most countries are trying to raise the brand image, withstand competition, and, most importantly, enter the world market. Therefore, standardization is a modern entrepreneurial strategy. Its influence and objectives cover all sections of public life. Standardization is a tool ensuring not only competitiveness, but also an effective partnership of manufacturer, customer and seller at all levels of management. In the future, for some goods and services, confirmation of conformity with the established requirements shall be carried out not only by certification, but also by a product 6

Introduction

manufacturer or a service provider. Under these circumstances, the role and responsibility of managers of organizations in competent application of standardization, metrology and certification rules by their staff increases. Compliance with the rules of metrology in various areas of commercial activity in the energy sector allows us to reduce the material losses from incorrect measurement results.

7

Section 1

METROLOGY AS THE SCIENCE OF MEASUREMENTS

Chapter 1

BASIC TERMS AND DEFINITIONS

1.1. The concept and main problems of metrology The word “metrology” in its formation consists of the Greek words “metro” – measure and “logos” – theory and means the theory of measures. The word “measure” generally indicates a means of assessing something. In metrology it has two meanings: as a unit designation (e.g. “square measures”) and as a means for reproducing a unit of measurement. In modern metrology, the term “measure of a physical quantity” means a measurement instrument intended for reproduction and storage of a physical quantity of one or several predetermined dimensions. Examples of measures are weights, measuring resistors, etc. According to the accepted definition, metrology is the science of measurements, methods and means of ensuring their unity and ways of achieving the required accuracy. The unity of measurements means the state, when the results of measurements are expressed in legal units of quantities, and the errors of measurement results are known with a given probability and do not go beyond the 10

Chapter 1. Basic terms and definitions

established limits. First of all, the unity of measurements is intended to ensure the comparability of measurement results obtained in different places and at different times using various methods and measuring instruments. This is due to the increasing growth of requirements in modern society to the accuracy and reliability of measurement information used in virtually all areas of activity – scientific, technical, economic and social. The content of the “unity of measurements” concept shall be detailed below, after studying the sections on unit values and measurement errors. Accuracy of measurements characterizes the proximity of their results to the true value of the measured value and reflects the proximity to zero of the measurement error. The subject of metrology as a measurement science consists of the following sections: – general measurement theory; – units of physical quantities and their systems; – methods of measurement and measuring instruments; – methods for determining the accuracy of measurements; – basis for ensuring the uniformity of measurements; – standards of units of physical quantities; – methods for transferring unit sizes from standards to working measuring instruments. Metrology consists of the following main sections: – theoretical (fundamental) metrology, the subject of which is the development of fundamentals of metrology, e.g. the general theory of measurements and the theory of errors, the theory of units of physical quantities and their systems, the theory of scales and verification schemes, etc.; – legal metrology, a set of metrological rules and norms mandatory for application to ensure the uniformity of measurements, which operate in the rank of legal provisions and are under the state control; – practical (applied) metrology, which solves the issues of practical application of theoretical metrology development and provisions of legal metrology, in particular, the issues of checking and calibration of measuring instruments.

11

12

Section 1. Metrology as the science of measurement

1.2. The concept of measurement Measurement is one of the most ancient operations in the process of human cognition of the surrounding material world. The whole history of civilization is a continuous process of formation and development of measurements, improvement of the methods and measurements means, increasing their accuracy and uniformity of measurements. During its development, the mankind has passed from measurements based on the senses and parts of the human body to the scientific foundations of measurements and use of sophisticated physical processes and technical devices for these purposes. Currently, measurements cover all physical properties of matter almost independently of the range of variation of these properties. Measurements have become increasingly important with the development of mankind in the economy, science, technology and production activities. Many sciences were called exact because they can establish quantitative relationships between natural phenomena using measurements. In fact, the entire progress of science and technology is inextricably linked with the increasing role and improvement of the art of measurement. D.I. Mendeleev used to say that “science begins when it is measured. Exact science is unthinkable without measurements”. Measurements are also important in technology, production activities, accounting of material values, ensuring of safe working conditions and human health, protection of the environment. Modern scientific and technological progress is impossible without the wide use of measuring instruments and numerous measurements. The term “measurement”, which to some extent includes all the other definitions, should be considered as the most preferable. The technical side of measurement as a set of operations on application of a technical device shows the metrological essence of measurement as a comparison process with a unit size (measure) and presents the cognitive side of measurement as a process of obtaining a value.

Chapter 1. Basic terms and definitions

The above definitions of measurement can be expressed by an equation, which in metrology is called the basic equation of measurement: X = {X}[X], where X is the value being measured; {X} is a numerical expression of the measured value; [X] is the unit. There is a concept of a quantity, or more exactly, a physical quantity in all definitions of measurement.

13

Chapter 2

GENERAL INFORMATION ON MEASUREMENTS

2.1. Specific features of the measuring process The concept of “measuring a physical quantity” is determined as a “set of operations on applying a technical device that stores a unit of physical quantity ensuring finding the ratio (explicitly or implicitly) of the measured quantity to its unit and obtaining the value of this quantity”. This interpretation of the concept of “measurement” reflects the following features: The latter factor is fundamental, distinguishing measurement from other information processes. A number can be expressed by a combination of characters in any numerical system, number of pulses, a combination of levels and any other accepted method. To implement the measurement process it is necessary to provide: – the ability to select the measured quantity among other quantities; – the possibility of establishing the unit necessary to measure the selected quantity; 14

Chapter 2. General information on measurements

– the possibility of materialization (reproduction or storage) of the established unit by technical means; – the possibility of maintaining the unit size unchanged (within the established accuracy) for at least the period necessary for measurements. There are other interpretations of the “measurement” concept. For example: “Measurement is the process of obtaining information, which consists in comparing experimentally measured and known values or signals performing the necessary logical operations and presenting information in numerical form”. Let us compare this with the first interpretation: “Measurement is a set of operations on applying a technical device that stores a unit of physical quantity ensuring finding the ratio (explicitly or implicitly) of the measured quantity to its unit and obtaining the value of this quantity”. This formulation complements the previous one that measurement is an information process; it assumes that measurement information is subsequently used either by a human operator or an automated system that processes, stores, and transmits this information. There is another definition: “Measurement means obtaining of a numerical equivalent (value) of a quantity characterizing the properties of a physical object (subject, process, phenomenon) by experiment (experimentally) that meets the requirements of the measurement assurance system, which is based on comparing an analogue value with the exemplary one”. Special attention is paid here to comparison and satisfaction of the measurement unity system requirements, which is caused by the inclusion of numerical transformations in the procedure. These features of measurements are highlighted due to the need to separate purely computational procedures for obtaining quantitative information from the measuring ones. Not only physical quantities can be measured, but also functional dependencies characterizing the properties of the measurement object. In this case, measurements are either carried out at fixed values of the argument (more often in time or spatial coordinates), or measurements

15

16

Section 1. Metrology as the science of measurement

of functions using a measure that reproduces the model dependence. If random variables are measured, the statistical measurements are taken where the input effect is considered as an implementation of a random process, and the purpose of the measurement is to determine an estimated value of a certain probability characteristic. Moreover, the measurement result must be tied to a point in time (or a point in space). The main objective of metrology is to ensure the unity of measurements. The unity of measurements means that the measurement results are expressed in generally accepted units, and the measurement error is known. Measurement can be defined as an experimental finding of a relationship between the measured physical quantity and another homogeneous quantity taken as a unit. Thus, the task of measurement consists in comparing the measured value with a preselected unit. In GOST, measurements are defined as finding the value of a physical quantity empirically using the special technical means. Physical quantity is a property qualitatively common to many objects, but quantitatively individual for each of them. For example, physical quantities are length, electric current, voltage, and inductance. The quantitative content of a physical quantity characterizing a particular object is called the size of a physical quantity (size of a quantity). The evaluation of a physical quantity in the form of a certain number of units accepted for it is called the value of a physical quantity. The term “parameter” is used to refer to the particular features of physical quantities. For example, a capacitor is characterized by capacitance, and its parameters can be considered as the loss angle tangent, temperature coefficient of capacitance, inductance of inputs. Sometimes the parameter is called the measured physical quantity – amplitude, phase. There are true and real values of a physical quantity. The true value ideally reflects the corresponding properties of the object in quantitative and qualitative terms, and we try to find it in measurements. However, due to the inevitable measurement errors, the true value cannot be obtained. In practice, instead of the true value, an

Chapter 2. General information on measurements

actual value is determined experimentally, so close to the true value that it can be used instead. 2.2. Measuring instruments Technical tools that have normalized metrological characteristics (characteristics that affect the accuracy of measurements) applied in the measurement are called the measuring instruments. Measuring instruments include measurement standards of physical quantities, measures, measuring devices, measuring transducers, measuring and computing complexes (MCC), computer-measuring systems (KMS) and measuring information systems (MIS). A measuring transducer is a structural element of more complex measuring instruments having independent metrological characteristics. There are primary, transmitting, intermediate and large-scale converters. The primary transducers are sometimes called sensors. Measuring devices and measures are created based on several measuring transducers. The measuring device is designed to form the output signal in a form that is available for direct perception by the observer. Measuring devices are divided into the analogue and the digital one. The analogue meter reading is a continuous function of the measured value. For example, the analogue meters include devices with arrow pointers. Digital instruments produce a discrete measuring information signal in digital form. The measure serves to reproduce the physical quantity of a given size. So, measures are an exemplary inductor or an exemplary variable capacitor. Measuring and computing complexes are a combination of measuring instruments and computers combined with the interface devices and intended for measurement, research and calculations. The same functions are performed by KIS based on the microcomputers supplemented by measuring modules.

17

18

Section 1. Metrology as the science of measurement

Measuring information system is a set of functionally combined measuring, computing and other auxiliary technical means designed to obtain measuring information, to convert and to process it in order to present it in a user-friendly form, or to provide automatic control, diagnostics or identification. Systems with a high degree of automation of the measurement process and processing of experimental results are sometimes referred to as automated measuring systems (AMS) or automated research systems (ARS). At present, devices consisting of a personal computer supplemented by a data acquisition board containing ADCs and model measures are becoming popular. The board converts the analogue measurement signal to the digital one; the computer performs the processing functions. The front panel of the measuring device with all the settings controlled by a computer keyboard or mouse is reproduced on the monitor screen for a visual display of information and ease of measurement process management. Such devices are called virtual. 2.3. Measurement classification Based on the method of obtaining measurement results there are direct, indirect, joint and cumulative measurements. Direct measurements are the measurements for which the desired value of a quantity is found directly from the experimental data. These include, for example, voltage measuring with a voltmeter or measuring a time interval with a time meter. In indirect measurements, the sought value Y is found from the known relationship between this quantity and the values X1., X2…Xn,, measured by the direct method: Y = f(X1,X2…Xn). For example, the measurement of the power dissipated by the resistor P = U2/R is indirect based on the results of direct measurements of the voltage U and the resistance of the resistor R.

Chapter 2. General information on measurements

Joint measurements are simultaneous measurements of two or more indifferent values to find the relationship between them. An example of a joint measurement is the dependence of the resistor on its temperature. Cumulative measurement is a simultaneous measurement of several like values, when the desired value is found by solving a system of equations obtained from direct measurements of various combinations of these values. Measurements related to measurement information processing, such as indirect, joint and cumulative, are often performed using the measuring instruments related to the computer equipment, for example, MCS or KIS. In this case, the processes of obtaining the experimental data and their processing are automated, and the result of calculations is displayed on the reading device. Formally, such measurements should be attributed to the direct ones, although they are indirect, joint, or cumulative. Test questions to the module 1. Give the definition of a physical quantity. Give examples of physical quantities related to mechanics, optics, magnetism and electricity. 2. What is the scale of a physical quantity? Give examples of different scales of physical quantities. 3. What is the dimension of a physical quantity? Record the dimensions of the following values: Pascal, Henry, Ohm, Farad, and Volts. 4. Give the definition of a system of physical quantities. Give examples of basic and derivative physical quantities and units. 5. Determine the basic principles of building the systems of physical quantities. 6. Name the derivatives of SI units having special names. 7. Name the reduced values of physical quantities using multiple and fractional units. 8. What is the unity of measurement? 9. Define the basic theories of metrology. 10. Name the main types of measurements. 11. Name the main measurement methods. 12. Describe the main types of measurement errors. 13. What methods correct the measurement results?

19

Chapter 3

MEASURING INSTRUMENTS

3.1. Weight measurement and control Measuring instruments are classified according to the principle of operation, structure, type of measured quantity. Their metrological characteristics are important. By purpose, the weight measuring and weight dosing devices can be divided into the following six groups: 1) discrete scales; 2) continuous scales; 3) discrete dispensers; 4) continuous dispensers; 5) exemplary scales, weights, mobile calibration tools; 6) special measurement devices. The first group includes: – various types of laboratory scales with special conditions and weighing methods, requiring high accuracy of indication; – table scales with the maximum weighing limit up to 100 kg used mainly in trade; 20

Chapter 3. Measuring instruments

– platform mobile scales and mortise scales up to 15 tons; – stationary platform scales, car scales, wagon scales (including weighing during motion); – scales for the metallurgical industry (these include charge feed systems for blast furnaces, electric car scales, scales for liquid metal, ingots, rolled products, etc.). The second group includes: – belt scales; – continuous weighing conveyors leading to continuous measurement of the mass of the transported material. The third group includes: – dispensers for cumulative accounting (fraction scales); – dispensers for bulk materials; – lines (automatic weight dosing in production of concrete, asphalt, glass batch, etc.). The fourth group includes: – dispensers with adjustable material feed to the conveyor; – dispensers with adjustable conveyor belt speed. The fifth group includes various metrological scales for testing, as well as weights and mobile means of verification. The sixth group includes various weighing devices used to determine not mass, but other parameters (e.g. counting or grouping of equilibrium parts or products, determination of engine torque, percentage of starch in potatoes, etc.). 3.2. Measurement and control of geometrical quantities Plane-parallel end pieces are designed to transfer the dimensions from the standard to the product. They have the shape of a rectangular parallelepiped with two flat mutually parallel measuring surfaces. Measuring rulers refer to ruling measures and are intended for measuring the dimensions of products by a direct method. The beam-type measuring tool is designed for absolute measurements of the linear dimensions of the outer and inner surfaces, as well as for reproducing dimensions when marking details.

21

22

Section 1. Metrology as the science of measurement

The angular gauge with a Vernier control is designed to measure angular dimensions and dimensions of parts with an accuracy of 2’. Micrometric instruments are designed for absolute measurements of external and internal dimensions, ledge heights, hole depths and grooves. The principle of operation is based on the use of a screw pair (screw-nut) to convert the rotational motion of the micrometer screw into a translational one. Measurement and control devices with mechanical conversion are based on transformation of small displacements of the measuring rod into large displacements of pointers (arrows, scales, light rays, etc.). Measurement and control instruments with optical and opticalmechanical conversion are based on a combination of optical schemes and mechanical transmissions. Measurement and control devices with pneumatic transformation allow us to control easily deformable parts, parts with microroughness, etc. The relationship between the flow area of the discharge channel and the weight flow of air through it is used for these linear measurements. The area of the flow channel varies by linear movement. Measurement and control devices with electrical and electromechanical conversion are characterized by the presence of a single source of energy – electrical current. The following electrical converters are used – inductive, capacitive, electronic and photoelectric devices. Inductive devices use the properties of a coil to change their reactance when changing some of its parameters that determine the inductance value of the coil L. The capacitance-based measuring systems use the principle of converting the linear dimensions of displacements to changes in electrical capacitance of the capacitor. Radioactive measuring devices are based on the use of the radioactive radiation properties: to penetrate the substance, dissipate the substance and ionize the substance. Calibers are objects or devices designed to verify that the sizes of the products or their configuration comply with established tolerances.

Chapter 3. Measuring instruments

3.3. Measurement and control of mechanical quantities 3.3.1. Methods and means of measurement and control of kinematic quantities The parameters of mechanical movement to be measured in practice are displacement, speed and acceleration. These are kinematic parameters and they are interrelated: knowing the displacement and the time of displacement, one can determine the speed and acceleration. In turn, the speed and displacement can be obtained from the known acceleration. The ranges of measured speeds and accelerations are extremely large. Conventionally, they are divided into subranges. Linear speeds (up to), m/sec: near-light speed.........................................3·106 cosmic speed..............................................2·104 speed of aviation objects...........................103 transport speed ..........................................50 industrial speed..........................................10 low technical speed...................................10-1 very low speed...........................................10-5 Angular speeds (up to), rad/sec: very large speed.........................................3·104 moderate speed..........................................102 low speed...................................................10 low technical speed...................................1 very low speed...........................................10-5 Accelerations (up to), m/sec3; very large...................................................2·105 large...........................................................103 moderate....................................................102 low.............................................................1 very low.....................................................10-5

23

24

Section 1. Metrology as the science of measurement

The motion parameters according to the nature of their change over time can be divided into parameters of translational, rotational, and oscillatory movements. Measurement and control devices designed to measure linear speeds are called speed meters, means for measuring and controlling angular velocities (rotational speeds) are called tachometers, and means for measuring accelerations are called accelerometers. If the parameters of vibration of machines, devices, structures are measured, the corresponding devices are called vibrometers. The instruments used to measure the parameters of the earth’s surface movement are called seismographs. The most common methods for measuring linear velocities of moving solids are: aerometric, compensatory, thermodynamic, correlation, Doppler, electromagnetic, etc. The aerometric method is based on measuring the velocity (dynamic) pressure head functionally related to the speed of a body moving in air. The compensation method is based on the automatic balancing of the total pressure and pressure developed by the air compressor. The thermodynamic method is based on measuring the temperature of the inhibited air flow using an open thermocouple and a shielded thermocouple. The turbine method uses the kinetic energy of air or a water flow to rotate a tangential or axial impeller. The frequency of rotation of the impeller shall be proportional to the speed of movement. Methods and tools for measuring and controlling the rotational speeds that are most widely used in engineering: centrifugal, magnetic-induction, electrical, induction and stroboscopic. The centrifugal method is based on the response of the sensitive element to the centrifugal force developed by unbalanced masses of the rotating shaft. The magnetic induction method is based on the dependence of eddy currents induced in a metal body on the rotation frequency. The electrical measurement method is based on the dependence of the generated voltage on the rotational speed.

Chapter 3. Measuring instruments

The stroboscopic method of measuring the angular velocity is based on the property of the eye to preserve the visible image for tenths of a second after its disappearance. Measuring instruments (MI) built on this principle are more precise than those considered above. Acceleration-measuring methods and devices. Means for acceleration measuring are called accelerometers. The inertial method, the method of differentiating the speed and the method of double differentiating the distance to a fixed base are used to measure linear accelerations. The inertial method is based on measuring the force developed by the inertial mass as it moves with acceleration. The methods of single or double differentiation are reduced respectively to the differentiation of the measured velocity or distance to the fixed base. Methods and tools for measuring vibrations. Three elements are always involved in measuring vibrations: a vibrating link, a source (non-vibrating) link and a device for measuring the motion of a vibrating link relative to a non-vibrating one. A device for vibration measuring is called the vibrometer. 3.3.2. Methods and means of measurement and control of dynamic quantities The dynamic quantities include: mass, force, pressure, mechanical stress, moment of force, mass flow rate, work, energy, power. There is a relationship between mass, force, moment, tension, and pressure. This allows using them to measure the same or similar methods and means of measurement. To measure the mass of the body (substance) weight measuring tools are used, which are briefly called the weights. Measuring devices designed to measure the forces are called the dynamometers (force meters). Tools for measuring the torque called the torque gauges (torsiometers) are close to the designation.

25

26

Section 1. Metrology as the science of measurement

To measure and control the pressure, various types of manometers, vacuum gauges, barometers are used. 3.3.3. Methods and means of measurement and control of mechanical properties of substances and materials The quality of products is largely determined by the mechanical properties of materials from which they are made. The main ones are the specific gravity, density, viscosity, hardness, elasticity, strength, rigidity, etc. Density is the mass of a substance contained in a unit volume. Specific gravity is the force of gravity per unit volume. Elasticity is the property of materials by internal forces to restore the original shape, distorted by external influence, after the cessation of this impact. Rigidity is the property of materials to resist elastic deformation. Plasticity is the property of metals to form plastically without destruction. Fatigue is the process of gradual accumulation of damage in metals under the action of cyclic loads leading to the formation of cracks and destruction. The material hardness is the resistance exerted by the material against penetration of a more rigid body of a certain shape and size into the surface of another body. Viscosity, or internal friction, is the property of fluid bodies to resist the movement of one part relative to another. Mechanical testing of metals. There are the following types of testing ща mechanical properties: – static (characterized by a smooth and slow application of the load to the tested sample, which allows us to measure the forces and deformations at any time of the test); – dynamic (characterized by a sharp change in the magnitude of the forces acting on the sample, which allows us to determine the viscosity or brittleness of the material);

Chapter 3. Measuring instruments

– tests for fatigue or endurance (characterized by the multiple repeated or alternating loads applied to the sample); – hardness tests (characterized by the penetration of a more solid body into the surface of the test body); – tests for wear and abrasion (used to determine changes in mechanical properties of materials on their surface after along exposure to friction forces); – technological tests (used to determine the suitability of a material for a particular technological process, as well as to judge about some properties of the material, e.g. plasticity). 3.4. Measurement and control of thermal quantities 3.4.1. Methods and means of temperature measurement and control Temperature is a statistical quantity characterizing the thermal state of the body and proportional to the average kinetic energy of its molecules. The unit of temperature is Kelvin (K). Temperature can also be measured in Celsius degrees (°C). It is impossible to measure temperature directly as, for example, we measure length. Therefore, temperature is determined indirectly – by changing physical, i.e. thermometric, properties of various bodies. For practical goals related to temperature measurement the International Practical Temperature Scale was adopted, which is mandatory for all metrological bodies. It is based on a number of reproducible equilibrium states (reference points) of certain substances, which are assigned specific temperature values. The methods, most widely used for measuring the temperature, are based on: – thermal expansion of liquid, gaseous and solid bodies (thermomechanical effect); – changes in pressure with temperature inside a closed volume (gauge);

27

28

Section 1. Metrology as the science of measurement

– changes in the electrical resistance of bodies with temperature (thermistors); – thermo-electric effect; – use of electromagnetic radiation of the heated bodies. К 2046.15 1812.15 1723.15 1373.15 1337.58 1235.08 933.25 717.75 692.73 505.1181 408.15 373.15 273.1 90.188 54.361 27.102 20.28 13.81 0.0

С 1773 1539 1450 1100 1064.43 961.93 660.10 444.60 419.58 231.9681 135 100 0.01 182.962 218.769 246.043 252.87 259,34 273,15 о

Platinum Pt melting point Iron Fe melting point Steel melting point Glass melting point Gold Аu point Silver Ag freezing point Aluminum Аl melting point Sulfur S Melting Point Zinc Zn point Stannum Sn freezing point Polymer melting point Water Н2О boiling point Triple point of water Н2О Oxygen О2boiling point Triple point of oxygen О2 Neon Ne boiling point Hydrogen H2 boiling point Triple point of hydrogen H2 Absolute zero

Devices intended to measure the temperature are called thermometers. They are divided into two large groups: contact and contactless. Contact temperature measurement. Expansion thermometers are widely used in contact temperature measurements. Liquid glass thermometers are structurally divided into engravedon-stem and technical thermometers with the embedded scale. The principle of their operation is based on the relationship between the temperature and the volume of thermometric liquid enclosed in a glass shell. Organic fillers are used as thermometric liquids: toluene, ethyl alcohol, kerosene, and pentane.

Chapter 3. Measuring instruments

Bimetallic and dilatometric thermometers are based on the property of solids to vary their linear dimensions differently with changes in the temperature. Liquid gauge thermometers are based on the use of the relationship between temperature and pressure of a thermometric substance (gas, liquid) that fills a hermetically sealed thermometer system. When the medium temperature changes, the pressure of the thermometric substance changes in a closed space, as a result of which the sensitive element (manometric spring) deforms and its free end moves. This movement is converted into a rotation of the recording arrow relative to the scale of the device. Depending on the thermometric substance, manometric thermometers are divided into gas, condensation and liquid. In gas thermometers, the bulb, capillary and manometric springs are filled with an inert gas (nitrogen, helium, etc.). In condensation thermometers, saturated vapors of some lowboiling liquids (acetone, methyl chloride, ethyl chloride) change pressure with temperature. In liquid thermometers, the thermo-system is filled with a well expanding liquid (mercury, kerosene, ligroin, etc.). Resistance thermometers. Resistance thermometer consists of a sensing element in the form of a thermistor, a protective cover and a connecting head. The principle of the sensitive element is based on the use of the substance electrical resistance dependence on temperature. The materials used for their manufacture are pure metals: platinum, copper, nickel and semiconductor. Thermoelectric thermometers consist of a thermocouple, a protective cover and a connecting head, they are based on the thermoelectric properties of the sensing element. The essence of the thermoelectric method is the appearance of an electromotive force in a conductor, the ends of which have different temperatures. Contactless temperature measurement. The temperature of a heated body can be determined based on measurement of its thermal

29

30

Section 1. Metrology as the science of measurement

radiation parameters, which are electromagnetic waves of various lengths. Thermometers with the action based on the measurement of thermal radiation are called pyrometers. Based on the laws of radiation, there are the following types of pyrometers: – cumulative (full) radiation, where the total radiation energy is measured; – partial radiation (quasi-monochromatic), where energy is measured in a limited part of the spectrum by a filter (or receiver); – spectral distribution, where the radiation intensity of fixed spectral regions is measured. 3.4.2. Methods and means of measuring and controlling thermophysical properties of substances and materials Thermophysical properties can be divided into several groups. The first group includes the equilibrium thermophysical properties of substances, which are functions of the state. This group includes the so-called thermodynamic properties (substance density, internal energy, enthalpy, entropy, heat capacity). The second group of thermophysical properties of substances includes “portable” properties, such as thermal conductivity, viscosity, diffusion. These properties characterize nonequilibrium processes in physical media. Some optical properties related to the absorption and emission of thermal radiation also belong to the thermophysical properties. Methods and means of measuring and controlling the thermophysical properties of substances and materials are quite diverse. The main instrument for measuring the physical properties of substances and materials is a calorimeter. It uses the direct heating method. Two groups of methods are used to determine the thermal conductivity of a substance: stationary and non-stationary. One of the methods widely applied for determining the thermal conductivity of metals is the method of longitudinal heat flux.

Chapter 3. Measuring instruments

3.5. Measurement and control of electrical and magnetic quantities Measurement of most of the electrical quantities is more or less related to the measurement of voltage or current. The most commonly used measuring device is a magnetoelectric instrument. A type of magnetoelectric device designed to measure the alternating voltages and currents is a rectifying system device. It is a combination of a magnetoelectric device with a rectifier circuit. The device of the ferrodynamic system widely used as an instrument for power measurement is a wattmeter. The electromagnetic system device is widely applied in industry. 3.6. Measurement of pressure, volume and flow rate of gases and liquids The widespread use of pressure, its differential and rarefaction in technological processes requires the use of various methods and means of pressure measurement and control. Pressure measurement methods are based on comparing the measured pressure forces with: – the liquid column (mercury, water) pressure of an appropriate height; – forces developed during deformation of elastic elements (springs of membranes, monometric and aneroid boxes, bellows and manometric tubes); – gravitational forces of loads; – elastic forces arising from the deformation of certain materials and causing electrical effects. Based on the above methods, the means for measuring the pressure parameters can be divided into liquid, deformation, dead-weight and electrical. The pressure measuring devices are divided into barometers (for atmospheric pressure measuring), manometers (for excess pressure measuring), vacuum gauges (for vacuum pressure measuring),

31

32

Section 1. Metrology as the science of measurement

pressure-vacuum meters (for excess and vacuum pressure measuring), absolute pressure gauges (for measuring the pressure counted from the absolute zero), differential pressure gauges (to measure the difference (differential) pressure). 3.6.1. Methods and means for measuring and controlling the flow rate and amount of gases and liquids Measuring instruments that determine the amount of a substance flowing through a cross section of a pipeline for a certain period of time are called quantity meters. Measuring instruments that determine the amount of a substance flowing through a cross section of a pipeline per unit of time are called flow meters. In addition to dividing all devices for volume and mass measuring, presented by quantity meters and flowmeters, there is a classification of their measurement methods according to the physical laws that underlie the principle of operation of these devices. The following measurement methods are used: – volumetric; – variable and constant pressure drop (throttling devices and flow meters); – velocity head (pressure pipes); – variable level (slit flow meters); – thermal, ultrasonic, electromagnetic, tachometric, inertial, optical, marker, etc. 3.6.2. Means for measuring and signaling the level of liquid Measurement, monitoring and signaling of the level of a liquid are of great importance in technology, especially, maintenance of technical systems with continuous liquid supply and removal. Means for measuring the level of a liquid medium are called level gauges. They are widely used to measure the amount of fuel in the

Chapter 3. Measuring instruments

tanks of vehicles – aircraft, cars, ships (they are called fuel gauges); for measuring the level of fuel in fuel storage facilities, the level of liquid (water) in boiler units, water-pressure systems, etc. There are the following methods for measuring the liquid level: float, gauge, capacitive, ultrasonic, radiation, radio frequency, etc. 3.7. Measuring instruments for direct conversion and comparison According to the structural principle of construction, measuring instruments are divided into devices of direct conversion and comparison. Direct conversion devices consist of measuring transducers connected in series, and a reading device, and their output signal is available for direct perception by the observer. For linear transducers, the total transfer ratio of the direct conversion device is y = KiKп(x),

(1.2)

where y and x are the output and input signals, Ki (i = 1, 2, ..., n) are transfer coefficients of measuring transducers, Kп is the transmission coefficient of transducers connected in series. The smallest value of the measured unit that can be detected using this device is called the threshold of sensitivity. The resolution of the instrument is usually estimated as the difference between two close values of the measured quantity, at which these values can be distinguished. For digital devices, as a rule, the threshold of sensitivity and resolution coincide and are equal to the division value of the low-order digit of the reading device. Sometimes resolution is defined as the number of values of a measurable quantity that can be distinguished within a measuring range. Comparison measurement tools implement the method of comparing the measured value with the value reproduced by measuring. They are built according to the structural scheme shown in Fig. 1.2. A direct conversion circuit consisting of measuring transducers con-

33

34

Section 1. Metrology as the science of measurement

nected in series has a negative feedback. The feedback is provided by a feedback converter that controls the measure. The comparator typically subtracts the xfdb feedback from the x input, so that the output of the measuring instrument is у = Кtr (х–хfdb). x

Comparing device

Transducer l

(1.3) Transducer n

y

Readout device

xoc Measure

Feedback transducer Fig. 1.2

Feedback signal хfdb = Кfdbу,

(1.4)

where Кос is the transfer coefficient of the circuit feedback. Comparison measurement tools can be implemented with complete and incomplete balancing. When fully balanced, x = хfdb and, therefore, y = x/Кfdb, and the transfer coefficient is К = 1 /Кfdb.

(1.5)

The transmission coefficient of such a measuring instrument is fully determined by the feedback coefficient Кос and does not depend on the transmission coefficient of the direct conversion circuit. The measurement method, where х = хfdb, is called a zero method. If the balancing is incomplete, then a differential method is used, by which the difference x – хfdb is measured. In this case Кfdb is the transfer coefficient of the circuit feedback. At that, the output signal is obtained from the joint solution of equations (1.3) and (1.4). Usually KtrKfdb > 1, therefore y = x/Kfdb, and

Chapter 3. Measuring instruments

К = 1/Kfdb. Hence, the transfer coefficient of the comparator is almost independent of the direct conversion circuit transfer coefficient and is determined by the reverse conversion circuit. Measuring instruments most often have a combined structure and contain several internal feedback circuits, and converters without a that are not covered by feedback. Test questions to the module 1. What is quality of measurements? 2. Describe the principles of measurement results processing. 3. What are the dynamic measurements and dynamic errors? 4. What is the basis of the calculated summation of errors theory? 5. Decipher the concepts of correlated and uncorrelated random variables. 6. How are random and systematic errors summed up? 7. Name the types of measuring instruments. 8. What does normalization of MI metrological characteristics mean? 9. Name the types of MI errors. 10. Describe digital MI errors. 11. What is the MI accuracy class? 12. What is the difference between the metrological characteristics of analogue and digital MI? 13. What caused the change in time metrological characteristics of MI? 14. What is a test and how is it different from a measurement? 15. What is control and how does it differ from measurement? What types of controls exist? 16. What is the probability of errors of the first and second kind? What do they characterize? 17. What are the main principles of the MI choice?

35

Chapter 4

PHYSICAL QUANTITIES AND THEIR VALUES

To build a system of units, it is first necessary to select a set of physical quantities. For example, systems of units for mechanical, thermal, electrical and magnetic, light and other quantities can be constructed. They can also be combined into one common system of units. A physical quantity is a property that is qualitatively common to many physical objects, but in quantitative terms it is individual for each object. Thus, the physical quantity is both a generalized concept (length, mass, temperature, etc., without being tied to a specific object), and an individual feature of an object or phenomenon (mass of a given body, magnetic field strength at a given point in space, etc.). If we mean the quantity in the second sense, the name of the object that characterizes the quantity, or the word “specific” is added to the name of the quantity. The unit is selected for each quantity; the unit in physical sense does not differ from the corresponding quantity, but has a well-defined, fixed size. Therefore, each specific value can be represented as a product of a unit and an abstract number: 36

Chapter 4. Physical quantities and their values

Х = [Х][Х],

(1)

where �������������������������������������������������������������� Х������������������������������������������������������������� is a quantity value; [X] is a numerical value (abstract number); [Х] is a unit of quantity X. In the case of a generalized quantity, its numerical value remains uncertain, in the case of a specific quantity, it depends on the quantitative content of the quantity in the object, i.e., on its size. According to its content, a specific quantity and its value are notions of different categories: a specific quantity can be measured using measuring instruments, and the value of a quantity is only information about a specific quantity, its reflection in the human mind. Although each specific quantity can be expressed in units, i.e. one can find its value, these categories should not be confused and the one should not tell, for example, about measuring the values of quantities. 4.1. Relations between quantities, physical equations Clusters of matter form objects of the material world of various complexity and composition. Objects do not exist in isolation, they interact with each other, and their states change, i.e. processes proceed in them. In general, it may be called as phenomena. For studying and describing the objects and phenomena, various physical quantities have been introduced, some of them (there are relatively few) are mutually independent. Several groups of independent quantities may be specified, e.g. length, mass, time, temperature, electric charge; length, time, strength, temperature; length, time, luminous flux, etc. Independent quantities are used either directly or to form the quantities derived from them. Thus, derived quantities are linked to independent quantities, as well as among themselves. For example: speed is the time derivative of the distance (i.e. length); impulse is a product of force and time (or mass and speed). Each object or phenomenon is characterized by a whole series of quantities, and during the transition from one object to other objects similar to it, they change in size.

37

38

Section 1. Metrology as the science of measurement

Relations between quantities existing both in individual objects and in sets of objects are usually described in mathematical form using equations. However, it is necessary to distinguish these equations from the purely mathematical ones, where symbols mean abstract numbers. In physical equations, the symbols mean physical quantities that are qualitatively different. Physical equations allow us to describe not only the quantitative, but also the qualitative part of the physical phenomenon, and to formulate physical laws. However, it should not be forgotten that physical equations are nothing more than descriptions in mathematical form (mathematical models) of certain physical situations; therefore, physical equations cannot be separated from these situations and viewed separately from them. 4.2. System of quantities When considering a particular group of phenomena, a certain set of quantities, connected by a system of defining equations, is used. Among them, a certain group of fundamental quantities is selected, which can be introduced independently of others and measured without measurements of other quantities. Such quantities are called basic, and the rest, called derivatives, are introduced by defining them through independent quantities or previously introduced derived quantities. This set of quantities, together with the system of defining equations and the models of objects or phenomena described by them, is called the system of quantities. The choice of basic quantities and their numbers is somewhat arbitrary. For example, to describe the mechanical phenomena, length, mass, and time are often taken as basic quantities, but in applied disciplines, sometimes force, the third basic value, is taken instead of mass. Dimension of quantities. There are many different opinions on the concept of “dimension”. There is no consensus even in what refers to dimension. Some authors believe that dimensions characterize the

Chapter 4. Physical quantities and their values

units and show how many times the size of the derived unit changes when the dimensions of the basic units change, others relate the dimensions to numerical values. The dimension is usually expressed by an exponential monomial with a coefficient equal to 1, where the dimensions of basic quantities serve as arguments. Therefore, the concept of “dimension” can be defined as a characteristic of a physical quantity, which in its most general form reflects its connection with the quantities adopted in this system as the basic ones. The dimension shows how this derived quantity changes during the transition from one object to another one similar to it, depending on changes in the basic quantities characterizing the objects. If, for example, for one object, the quantity X can be expressed as a function of length, mass, and time, i.e. in the form of X’ = k(l’)’(m’)β (t’)γ and for the other one in the form of X’’ = k(l’’)’(m’’)β (t’’)γ, then to define the quantity X” based on the quantity Х’, it is necessary to multiply the latter one to the number (l’’/ l’)×(m’’/ m’)×( t’’/ t’) equal to their ratio. In general, this number depends on the dimension of the quantity X, which according to the international standard is denoted as dim X = Lα Mβ Тγ, where dim is a dimension sign (abbreviation of the word “dimension”). Similarly for units, the dimension determines the ratio of derived units [X]”/ [X]’ of the quantity X in two coherent (linked) systems with different basic units in size. We will further discuss only the dimensions of quantity, for simplicity. Dimensions not only have a quantitative content, but to some extent they also reflect the qualitative side of quantities, their place in the dimensional system. The qualitative side of dimensions is emphasized by the fact that there are no operations of addition and subtraction for them: these operations do not lead to a new dimension. In contrast, multiplication and division of dimensions can lead to dimensions of other physical quantities. However, the dimensions do not fully reveal the “quality”, i.e. the physical content of quantities: it is known that there are many quantities that are completely different in physical content, but have the

39

40

Section 1. Metrology as the science of measurement

same dimensions. Such are the work and the moment of force (dimension L2MT-2), kinematic viscosity and thermal diffusivity (dimension L2Т-1), etc. Dimension is a more general characteristic of a quantity than the equation defining it, since the same dimension can be inherent to quantities determined by different equations. Thus, the work A of force F on the path s is determined by the equation A = Fs, and the kinematic energy E of a material point with mass m at speed v – by the equation E = mv2/2, whereas the dimensions of these quantities are the same. Equality of dimensions is not determined by the physical content, but only by the same relation of the quantity to the main quantities. However, the dimensions have a number of useful applications, in particular, for checking the homogeneity of equations, analyzing dimensions, modeling complex objects or phenomena, and forming derived units. The table presents the examples of the governing equations for certain quantities of mechanics and their dimensions in this system. Table 1 Name of the quantity

Governing equation

Dimen- Name of the sion quantity

Governing equation

Dimension

Length

l

L

Density

r

L-3M

Mass

m

M

Force

F = ma

LMT-2

T

Pressure

P = F/S

L-1MT-2

Time Square

S = ab

L2

Work

A = Fl

L2MT-2

Volume

V = abh

L3

Power

P = A/t

L2MT-3

Speed

v = dl/dt

LT-1

Acceleration

a = dv/dt

LT-2

The quantity with the dimension where all indicators are equal to zero is dimensionless in this system.

Chapter 4. Physical quantities and their values

4.3. Characteristics of international system of units and definition of basic SI units In our country, as in most countries of the world, the international system of SI units has been adopted. The basic units of the system are meter, kilogram, second, ampere, kelvin, candela, mole, and additional units are radians, steradians. Derivative units – volts, watts, joules, and others – are formed from the basic and additional units based on the dependencies linking these parameters. For example, the amount of electricity is determined by multiplication of current and time. Some other units, which have proven to be convenient in some areas or have been preserved by virtue of tradition, are also allowed to be used and are widely used. These units include plane angle units (degrees, minutes, seconds), pressure units (mm Hg). The basic SI units are listed in Table 2. Table 2

Name

Quantity

Length Mass Time Electric current Thermodynamic temperature Amount of substance Luminous intensity

Dimension L M T I Q N J

Name Meter Kilogram Second Ampere Kelvin Mole Candela

SI Unit Symbol international m kq s A K mol cd

Russian м кг с А К ­моль­ кд

A meter is equal to the length of 1,650,763.73 wavelengths of radiation in a vacuum, corresponding to the transition between the levels of 2p10 and 5d5 of the krypton-86 atom. A kilogram is equal to the mass of an international kilogram prototype. A second is equal to 9,192,631,770 periods of radiation, corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom.

41

42

Section 1. Metrology as the science of measurement

An ampere is equal to the strength of an unchanging current that, when passing through two parallel straight conductors of infinite length and a negligibly small circular cross-sectional area located in a vacuum at a distance of 1 m from one another, would cause the interaction force equal to 2×10-7 Н on the 1m section of the conductor. A kelvin is equal to 1/273.16 parts of the thermodynamic temperature of the triple point of water. A mole is equal to the amount of a substance of a system containing as many structural elements as there are atoms in carbon-12 with a mass of 0.012 kg. A candela is equal to the intensity of light in a given direction of a source emitting monochromatic radiation at a frequency of 540×1012 Hz, the light intensity of which in this direction is 1/683 W/m. Two additional units are radian (a plane angle) and steradian (a solid angle). A radian is equal to the angle between two radii of a circle, the length of the arc between which is equal to the radius. A steradian is equal to the solid angle with the top in the center of the sphere, cutting an area on the surface of the sphere equal to the area of a square with a side equal to the radius of the sphere. The names and designations of most of the SI derivatives are formed as combinations of names or designations of basic and additional SI units, for example, meter per second, meter per second squared, kilogram per cubic meter, etc. However, some derived SI units have special names and symbols (in honor of scientists). 4.4. Standards of physical units To provide uniformity of measurements, it is necessary to have measuring instruments reproducing and storing dimensions of units of physical quantities, and to transfer these units to working measuring instruments. Physical quantities can be reproduced with the highest accuracy using the standards of units of physical quantities ensuring uniformity of measures and uniformity of measurements. Depending on the purpose, there are several types of standards. A primary standard is a standard providing reproduction of a physical

Chapter 4. Physical quantities and their values

quantity unit with the highest accuracy in the country. Special standards reproduce the unit under special conditions where the primary reference is not operational. For example, the primary standard EMF reproduces the unit voltage at a constant current. EMF standards for the frequency ranges of 20 Hz...30 MHz and 30 MHz...3 GHz are special. Standards reproducing a unit of the same physical quantity in different frequency ranges may differ significantly in their structure and can be built on different measurement principles. Primary or special standards officially approved as basic for the country are called state standards. Applied metrological activities use secondary standards, witness standards, comparison standards and working standards. The witness standard serves to check the safety of the state standard or its replacement in case of damage or loss. The reference standard is designed to transmit the reproduced primary standard size when comparing the standards that cannot be compared with each other due to impossibility of their transportation. The working standard is intended to transfer the size of a physical unit to a working measuring instrument. In the literature there is also an outdated name of working standards – exemplary measuring instruments. At present, there are 52 state standards in our country. Characteristics of some of them are given in Table 3. Table 3

Standards and their characteristics Physical quantity

Range of values

Time and frequency EMF

10–9…108 sec 1…1016 Hz 0,1…1 W 0,1…1 W

Amperage

1 1012…30 А 0,01…10 А 3…100 А – – –

Capacity Inductance

Frequency range or operating frequency – Constant 20…3 107 Hz 30…3000 MHz D.C 40…1 105 Hz 0,1…30 MHz 1 kHz 1…100 MHz 1 kHz

Standard deviation of random error 5 10–14 5 5 5 4 1 5 2 3 1

108 10–5 10–3 10–6 10–4 10–4 10–7 10–5 10–6

Limits of nonexcluded systematic error 2 10–13 1 2 3 8 2 8,5 5 1 5

10–6 10–4 10–2 10–6 10-4 10–4 10–7 10–4 10–6

43

44

Section 1. Metrology as the science of measurement

To reproduce units in a wide range of frequencies, several standards have to be created. For example, three standards were developed for voltage. The error of the standard is characterized by the standard deviation of the error, as well as by the non-excluded systematic error. Analysis and summation methods for these components of the total error are considered in Chapter 4. The non-excluded systematic error, which basically determines the total error in the reproduction of a unit of physical quantity, prevails almost for all standards. Time and frequency are reproduced with the smallest inaccuracy. The reproduction errors of the main parameters, such as current, voltage, resistance, sharply, sometimes increase two or three times with an increase in the operating frequency, and the reproduction error may even increase to 102...103. Increasing demands to accuracy of measurements in various areas of the national economy stimulate creation of new special standards and an increase in accuracy of the existing ones. When developing standards, experts try to use stable physical phenomena and processes, the reproduction of which is provided by the fundamental laws of physics and does not depend much on the specific features of the construction of standards. An example of such an approach is the State Primary Standard of Time and Frequency approved in 1983. It is based on the resonance absorption of an electromagnetic wave by cesium atoms. 4.5. Metrological characteristics of measuring instruments (MI) The assessment of the measuring instrument suitability for solving various measurement tasks is carried out by considering their metrological characteristics. Metrological characteristic (MC) is a characteristic of one of the properties of a measuring instrument influencing the result of measurements and its error. Metrological characteristics allow us to judge

Chapter 4. Physical quantities and their values

about their suitability for measurements in a known range with known accuracy. The metrological characteristics established by the normative documents on measuring instruments are called the standardized metrological characteristics, and those determined experimentally are valid. For each type of MIs their own metrological characteristics are set. Further the most common metrological characteristics are considered. The range of MI measurements is the range of values within which its permissible limits of error are normalized. For measures, it is their nominal value; for converters – the conversion range. The lower and upper measurement limits are the values of the quantity limiting the range of measurements from the bottom and top. MI error is the difference between the indication of the measuring instrument – Хinst and the true (real) value of the measured quantity – Хreal. There is a common classification of measurement errors. The examples of their most commonly used types are given below. MI absolute error is the error of the measuring instrument expressed in units of the measured value: ������������������������ D����������������������� temperature������������ (20 ± atmo����� spheric pressure (100 ± 4) kPa or (750 ± 30) mm Hg.; – supply voltage of the electrical network 220 V ± 2% with a frequency of 50 Hz. Sometimes, instead of the nominal values of the influencing quantities, the normal range of their values is indicated. For example, humidity (30 – 80) %. Additional MI error is a component of the MI error arising in addition to the basic error due to deviation of any of the influencing values from its normal value. The division of errors into basic and additional is due to the fact that the properties of measuring instruments depend on external conditions. Errors in their origin are divided into systematic and random.

45

46

Section 1. Metrology as the science of measurement

Systematic MI error is a component of the measuring instrument error considered as constant or regularly changing. Systematic errors are generally functions of the measured quantity and the influencing quantities (temperature, humidity, pressure, supply voltage, etc.). Random MI error is a component of the measuring instrument error, changing randomly. Random measuring instruments errors are due to random changes in the parameters of the components of these MI elements and random errors of reference readings devices. When designing the device, its random error is tried to be made insignificant compared to other errors. The random error is negligible in a well-designed and manufactured device. However, with increasing sensitivity of measuring instruments, an increase in random error is usually observed. Then, with repeated measurements of the same value in the same conditions, the results will be different. In this case, it is necessary to resort to multiple measurements and to statistical processing of the results obtained. As a rule, the random error of the instrument is reduced to such a level that does not require multiple measurements. MI stability is a quality characteristic of a measuring instrument reflecting constancy of its metrological characteristics in time. MI calibration characteristic is a relationship between the values of the input and output measurements obtained experimentally. It can be expressed as a formula, a graph or a table. 4.6. Use of MI In terms of applications, depending on the measurement task to be solved and further use of the measurement results of measuring instruments, measuring instruments can be divided into standardized and non-standardized.

Chapter 4. Physical quantities and their values

Standardized MI is a measuring instrument manufactured and applied in accordance with the requirements of a state or an industry standard. Standardized measuring instruments are usually tested and registered in the State Register. Non-standardized MI is a measuring instrument, the standardization of requirements for which are recognized as inexpedient. Nonstandardized MIs usually include highly specialized measuring instruments made in a single copy and not intended for mass production. Measuring tasks solved using such measuring instruments are limited and local. As a rule, such measuring instruments are used at one or several enterprises for auxiliary measurements. Often they are used as indicators. The concept of a standardized measuring instrument is close to the concept of a legalized measuring instrument. Legalized MI is a measuring instrument recognized as valid and approved for use by an authorized body. Examples of legalized measuring instruments are: state standards become such as a result of approval by the national standardization body, working measuring instruments for mass production, which are legalized by type approval (see below). All measuring instruments are divided into types and kinds. Type of measuring instruments is a set of measuring instruments of the same purpose based on the same principle of operation, having the same design and manufactured according to the same technical documentation. That is, the type of measuring instruments is absolutely identical devices, differing only in serial numbers. In contrast to the type there are kinds of measuring instruments, consisting of a wider range of them. Kind of measuring instruments is a set of measuring instruments designed to measure this physical quantity. The kind of measuring instruments may include several types. For example, an ammeter is a kind of measuring instrument for measuring the current strength.

47

48

Section 1. Metrology as the science of measurement

The possibility or impossibility of using a measuring instrument to solve the set measurement task is characterized by such concepts as metrological serviceability and metrological failure. Metrological serviceability of an MI is the state of measuring instruments, where all standardized metrological characteristics correspond to the established requirements. Then they can be used in accordance with their purpose and metrological characteristics. Metrological failure of MI is overrunning of the metrological characteristics of the measuring instrument beyond the established limits. If the metrological failure occurred due to technical problems, they should be eliminated. If the device is technically sound, then in case of a metrological failure, its accuracy class should be lowered. 4.7. Normalization of MI errors Measuring instruments can only be used when their metrological characteristics are known. Usually, the nominal values of the measuring instrument parameters and the permissible deviations from them are indicated. Information about the metrological characteristics is given in the technical documentation for measuring instruments or is indicated on them. As a rule, real metrological characteristics have deviations from their nominal values. Therefore, limits are established for deviations of real metrological characteristics from nominal values – they normalize them. Normalization of metrological characteristics of measuring instruments allows us to avoid arbitrary establishment of their characteristics by developers. With the help of standardized metrological characteristics, the following main tasks are solved: – preliminary calculation of errors of the results of technical measurements (prior to measurements);

Chapter 4. Physical quantities and their values

– selection of measuring instruments according to specified characteristics of their errors. Standardization of the MI characteristics is carried out under the provisions of the standards. For example, GOST 8.009-84 “GSI. Standardized metrological characteristics of measuring instruments”. Compliance of measuring instruments with the norms established for them makes these instruments interchangeable. One of the most important metrological MI characteristics is the error, knowledge of which is necessary for estimating the measurement error. It should be noted that the MI error is only one of the components of the measurement result error obtained using this MI. Other components are the measurement method error and the error of the operator conducting the measurement. Errors of measuring instruments may be caused by various reasons: – non-ideal properties of the measuring instrument, i.e. the difference of its real conversion function from the nominal one; – influence of affecting quantities on the properties of measuring instruments; – interaction of the measuring instrument with the measurement object – a change in the value of the measured value due to the measuring instrument impact; – methods for processing the measurement information, including the computer technology. The errors of specific MI copies are set only for standards; for the rest of MI, all information about their errors represents the norms that are set for them. The standardization of errors is set forth in OIML Recommendation 34 “Accuracy Classes of Measuring Instruments” and in GOST 8.401-80 “Accuracy Classes of Measuring Instruments. General requirements”. Normalization of errors of measuring instruments is based on the following main provisions. 1. The limits of permissible errors, including systematic and random components are indicated as the norms.

49

50

Section 1. Metrology as the science of measurement

The limit of permissible error is the highest value of the measuring instrument error, at which it is still recognized as suitable for use. Usually the limits, i.e. values which the error should not exceed, are predetermined. This provision reflects the statement that measuring instruments can be used with a single reading. 2. All MI properties affecting their accuracy are normalized separately: the basic error is normalized separately, and all additional errors and other properties affecting the measurement accuracy are normalized separately. When this requirement is fulfilled, maximum homogeneity of measuring instruments of the same type is ensured, i.e. close values of additional errors due to the same factors. This makes it possible to replace one device with another one of the same type without a possible increase in the total error. Limits of permissible errors of measuring instruments are applied to both absolute and relative error. The limits of permissible absolute error are set for additive error by the formula ∆ = ± А. For multiplicative error, they are set as a linear dependence ∆ = ± (А + bх), where x is the meter reading, a and b are positive numbers independent of x. The limit of permissible relative error (in relative units) for the multiplicative error is established by the formula δ = ∆ / х = ± c. For additive error, the formula is: δ = ∆ / х = ± [ c + d ( xk / x – 1)], where хk is the final value of the measuring range of the device; and c and d are the relative values.

Chapter 4. Physical quantities and their values

The first term in this formula makes sense of the relative error at x = хk, the second one characterizes the growth of the relative error with decreasing instrument readings. Limits of permissible reduced error (in percent) should be set by the formula γ = 100∆/хN = ± р, where хN is the normalizing value; р is an abstract positive number from the row 1; 1.5; 2; 2.5; 4; 5; 6, multiplied by 10n (n = 1, 0, -1, -2, etc.). The normalizing value is assumed to be: the final value of the scale (if 0 is on the edge of the scale), the sum of the final values of the scale (if 0 is inside the scale), the nominal value of the measured value, the length of the scale.

51

Chapter 5

MEASUREMENT ERRORS

5.1. The concept of measurement error The task of measurement is to determine the values of the measured value. As a result of measuring a physical quantity with a true value of Хtrue, we obtain an estimate of this quantity, Хmeas – the measurement result. Here, two concepts should be clearly distinguished: the true values of physical quantities and their empirical manifestations – real values, which are the measurement results and in a specific measurement task can be taken as true values. The true value of the quantity is unknown and it is used only in theoretical studies. The measurement results are products of our knowledge and are approximate estimates of the values of quantities that we get in the process of measurement. The degree of approximation of the obtained estimates to the true (real) values of the measured values depends on many factors: the measurement method, the measuring instruments and their errors, the properties of the sensory organs of the operators conducting the measurements, the conditions under which the measurements are taken, etc. Therefore, there is always a difference between the true value of a 52

Chapter 5. Measurement errors

physical quantity and the measurement result, which is expressed by the measurement error (the same as the measurement result error). Measurement result error is a deviation of the measurement result from the true (real) value of the measured value: ∆X = Xmeas – Xtrue . Since the true value of the measured value is always unknown and in practice we deal with real values of ХR quantities, the formula for determining the error is: ∆X = Xmeas – X∂ . 5.2. Object models and measurement errors The task of measurement is to obtain the values of a physical quantity characterizing the corresponding properties of the real object of measurement. However, due to the fact that we do not know the true value of the quantity being measured, the question is: what then should we measure? To answer this question, we introduce a certain idealized image of the object of measurement – the model of the measurement object, the corresponding parameters of which can be best represented as the true value of the measured quantity. The model of a real measurement object usually represents a kind of its abstraction and its definition is formed based on logical, physical and mathematical representations. As an example, we consider the solution of the simplest measurement problem often considered in the literature – determining the diameter of a disk. A real object of measurement is a disk represented by its mathematical model – a circle. It is assumed that the diameter of the circle ideally reflects the property of the real disk, which we call its diameter. By definition, the diameter of the circle is the same in all directions, therefore, to check the compliance of our model with a real object (disk), we should measure the disk

53

54

Section 1. Metrology as the science of measurement

in several directions. Based on the obtained measurement results two conclusions can be made. If the spread of the measured values, i.e. the differences in the measurement results among themselves do not exceed the measurement error of the disc diameter specified in the measurement task, then any of the obtained values can be taken as the measurement result. If the difference in the measurement results exceeds the specified measurement error, it means that the adopted model is not suitable for this measurement task and it is necessary to introduce a new model of the measurement object. Such a model, for example, may be a circle having a diameter equal to the largest measured value (describing the circle). Another example is the measurement of the area of a room. Representing the floor of the room in the form of a rectangle, its area can be found as the product of the room length by its width. But if it turns out that the width of the room is not the same along its length, then it is necessary to adopt another model – e.g. to represent the floor of the room as a trapezoid and to determine the area using a different formula. Similarly, the measurement model introduces the concept of a measurement error model. For example, the division of errors according to their origin, properties, methods of expression, etc. Therefore, the probabilistic models are most often used to express random errors. The random error is characterized not by a single value, but by a range of values where it can be found with a certain probability. The laws of its distribution and parameters of these distributions, which are indicators of the error, as well as the statistical methods for estimating these parameters by the measurement results are established for the selected error model. Details of the measurement error model will be discussed below. 5.3. Classification of measurement errors The above classification of measurement errors is related to the reasons for their occurrence. In addition, there are other signs by which errors are classified.

Chapter 5. Measurement errors

By the character of manifestation (properties of errors), they are divided into systematic and random, according to the ways of expression – to absolute and relative. The absolute error is expressed in units of the quantity being measured, and the relative error is the ratio of the absolute error to the measured (real) quantity value and its numerical value is expressed either in percent or in fractions of a unit. Experiments in measurements prove that for repeated measurements of the same constant physical quantity under constant conditions, the measurement error can be represented as two terms, which manifest themselves differently from measurement to measurement. There are factors that constantly or regularly change in the process of measurement and affect the measurement result and its error. Errors caused by such factors are called systematic errors. Systematic error is a component of measurement error remaining constant or regularly changing for repeated measurements of the same value. Depending on the nature of the change, systematic errors are divided into constant, progressive, periodic, varying according to a complex law. The closeness of systematic error to zero reflects the accuracy of measurements. Systematic errors are usually estimated either by theoretical analysis of measurement terms based on the known properties of the measuring instruments, or by using more accurate measuring instruments. As a rule, we try to eliminate systematic errors with the help of corrections. The correction is a value entered in the uncorrected measurement result to eliminate the systematic error. The value of the correction is opposite to the value of the quantity. The occurrence of errors is also influenced by factors that appear irregularly and suddenly disappear. Moreover, their intensity also does not remain constant. The results of measurement in such conditions have differences that are individually unpredictable, and their inherent patterns appear only with a significant number of measurements. The errors resulting from the action of such factors are called random errors. Random error is a component of the measurement error changing randomly (by sign and value) during the repeated measurements of the same quantity carried out with the same accuracy.

55

56

Section 1. Metrology as the science of measurement

The insignificance of random errors indicates a good convergence of measurements, i.e. proximity to each other of the results of measurements made repeatedly by the same means, the same method, under the same conditions and with the same accuracy. Random errors are detected by repeated measurements of the same magnitude under the same conditions. They cannot be excluded empirically, but can be evaluated by processing the results of observations. The division of measurement errors into random and systematic is very important, since accounting and evaluation of these components of error requires different approaches. As a rule, factors causing errors can be reduced to a general level, when their influence on formation of errors is more or less the same. However, some factors may appear unexpectedly strong, e.g. a sharp voltage drop in the network. In this case, errors may occur that significantly exceed the errors justified by the conditions of measurements, the properties of measuring instruments and the method of measurements, and the qualifications of the operator. Such errors are called gross or spurious errors. Gross or spurious error is the error of the result of an individual measurement included in a series of measurements, which for the given conditions differs sharply from the other error values. Rough errors should always be excluded from consideration if it is known that they are the result of obvious errors during measurements. If the reasons for appearance of sharply distinguished observations cannot be established, then statistical methods are used to resolve the issue of their exclusion. There are several criteria that allow identifying the gross errors. Some of them are discussed below in the section on processing the measurement results. 5.4. Random errors 5.4.1. Statistical stability of observations distribution In case of random measurement errors the repeated observations and subsequent statistical processing of their results should be used. The results of observations and measurements and random errors are

Chapter 5. Measurement errors

considered as random variables, i.e. variables that characterize a random phenomenon and as a result of measurements take one or another value. Processing of the results of such observations is possible if their dispersion reveals certain statistical patterns. If the results of observations are scattered arbitrarily, then it is not possible to use any methods of processing of such observations and to obtain a measurement result. Therefore, when formulating a specific measurement task and obtaining observation results, it is first necessary to check the presence of patterns in the distribution of observations. If such patterns are detected, the distribution of observations is statistically stable, and methods of the probability theory and mathematical statistics can be used to process them. It should be noted that the detection of statistical regularities in the distribution of the observations results is carried out after excluding all known systematic errors. 5.4.2. Examples of random variables distribution Ways of finding values of a random variable depend on the type of its distribution function. However, in practice, such functions are usually unknown. If the random nature of the observation results is due to measurement errors, it is believed that the observations have a normal distribution. This is due to the fact that measurement errors consist of a large number of small perturbations, none of which is predominant. According to the central limit theorem, the sum of an infinitely large number of mutually independent infinitesimal random variables with any distributions has a normal distribution. The normal distribution for the random variable x with the mathematical mean value m1 and variance σ is written as: 1 f (x ) = e σ 2π

− ( x − m1 ) 2 2σ2

.

In reality, even the impact of a limited number of disturbances leads to a normal distribution of measurement results and their errors.

57

58

Section 1. Metrology as the science of measurement

Currently, the most fully developed mathematical apparatus is for random variables with a normal distribution. If the assumption of normal distribution is rejected, the statistical processing of the observations becomes much more complicated and in this case it is impossible to recommend a general method of statistical processing of the observations. Often, it is even unknown which characteristic of the distribution can serve as an estimate of the true value of the measured quantity. The above is an analytic expression of the normal distribution for a random measured quantity x. Transition to the normal distribution of random errors is carried out by transferring the center of distributions to and putting the errors along the abscissa axis . The normal distribution is characterized by two parameters: the mathematic mean value m1 and the standard deviation σ. In case of multiple measurements, the unbiased, consistent and effective estimate of m1 for a group of n observations is the arithmetic average : n

x=

∑x i =1

n

i

.

It should be noted that the arithmetic average gives an estimate of the mathematic mean value of the observations result and can be an estimate of the true (real) value of the measured value only after the exclusion of systematic errors. The estimated S of the sigma is given by the formula:

S2 =

n 1 ⋅ ∑ ( xi − x ) 2. n − 1 i =1

This estimate characterizes scattering of single measurement results in a series of equal measurements of the same magnitude around their average value. Other estimates of the dispersion of results in a series of measurements are span (the difference between the highest and lowest val-

Chapter 5. Measurement errors

ues), the modulus of the average arithmetic error (an arithmetic sum of errors divided by the number of measurements), and the confidence limit of error (discussed in detail below). Sigma is the most convenient characteristic of the error in case of its further conversion. For example, the sigma of the sum for several uncorrelated terms is determined by the formula:

S=

n

∑S

2

.

i =1

The estimated S characterizes scattering of single observations with respect to the average value, i.e. if we take the individual corrected observation result for the measurement result. If the arithmetic average is taken as the measurement result, the mean sigma is determined by the formula: n

S (x) =

∑ (x i =1

i

− x)

n(n − 1)

.

The normal error distribution has the following properties: 1) symmetry, i.e. errors of the same magnitude, but opposite in sign, occur equally often; 2) mathematical mean value of a random error is zero; 3) small errors are more likely than large ones; 4) the smaller the σ, the smaller the scattering of the observations results and the greater the probability of small errors. Another distribution of a random variable that is widespread in metrology is the uniform distribution, a distribution when the random variable takes values within a finite interval from х1 to х2 with a constant probability density. The differential uniform distribution function is: f(x) = с at х1 ≤ x ≤ х2 f(x) = 0 at х2 < x < х1

59

60

Section 1. Metrology as the science of measurement

In case of normalizing the distribution curve area by one, we have: с(х2 – х1) = 1 and с = 1/ (х2 – х1). Uniform distribution is characterized by the mathematical mean value m1 =

x –x x − x1 x1 + x 2 , variance σ = 2 Dx = 2 1 2 12 2 3

or sigma.

Apart from the considered examples of random variables distributions, there are other important distributions for practical use of the distribution of discrete random variables, e.g. the binomial distribution and the Poisson distribution. They are not considered in this course. 5.5. Systematic errors Detection and elimination of systematic errors is a complex task that requires in-depth analysis of the entire set of observations, tools, methods and conditions of used measurements. It should be noted systematic errors are elimitated not by mathematical processing of the observations results, but by appropriate measurement methods. In particular, by measuring with various independent methods or by measuring with parallel use of more accurate measuring instruments. There are some special methods of measurement allowing us to exclude parts of systematic errors: 1. Exclusion of the source of errors itself. 2. Replacement of the measured value by a known value equal to it so that no changes occur in the state and action of all the measuring instruments used. In this way, the comparator error can be eliminated. 3. Compensation of the error in the sign by measuring in the forward and reverse directions with the same device. For example, determining the value of the measured value when approaching a certain point of the scale to the left and right of it and calculating the average value. 4. Observations through a period of changes in the influencing quantity. This allows us to exclude the errors varying according to the periodic law.

Chapter 5. Measurement errors

5. Measurements of one quantity by several independent methods with the subsequent calculation of the average weighted value of the measured quantity. 6. Measurements of one quantity by several instruments followed by calculation of the arithmetic average of the readings of all instruments. Systematic errors are eliminated by introducing differently found corrections, which are the values of absolute errors that are subtracted from the measurement result. Thus, the instrumental components of systematic error are found by the results of calibration of measuring instruments. Corrections accounting for influencing quantities are calculated using known functions or influencing factors based on the results of auxiliary measurements of these quantities. But the introduction of corrections does not fully exclude the systematic errors, since, for example, errors in the determination of corrections still remain there. These non-excluded parts are the non-excluded residuals of systematic errors (NSE). Since it is impossible to completely eliminate the systematic errors, the task of estimating the boundaries or other parameters of these errors arises. As a rule, the systematic error of the measurement result is estimated by its components. These components are either known in advance, or can be determined using auxiliary data, e.g. calculated for each of the influencing quantities. The errors of determination of corrections may serve as these components. Nonexcluded systematic error is characterized by the boundary of each of its components. In this respect, the task of summing up the components of a systematic error arises. In this case, the components should be considered as random variables and summed by the methods of probability theory, which implies knowledge of the distribution function of these components. However, as a rule, the law of distribution of the elementary error components is unknown. Therefore, during the summation the following practical rule based on common sense and intuition is used: 1. if the error limits estimate is known, its distribution should be considered as uniform;

61

62

Section 1. Metrology as the science of measurement

2. if the sigma error estimate is known, the distribution should be considered as normal. Application of this rule allows us to sum up the components of systematic error statistically. In accordance with it, in the absence of additional information, non-excluded residuals of systematic error are considered as random variables with a uniform distribution. The boundaries of non-excluded systematic error Θ when the number of terms is greater than or equal to 4 are calculated by the formula:

Q=k⋅

∑ϑ i

2 i

,

where is the limit of the i-th error component; k is the confidence factor. With Р = 0.95, k = 1.1, with Р = 0.99, k = 1.4. When the number of terms is fewer than or equal to 3, the values ϑ1 are summed arithmetically by module. If, however, we sum up the NSE arithmetically with any number of terms, the resulting estimate will be overestimated, albeit reliable. The confidence probability for calculating the boundaries of the non-excluded systematic error is assumed to be the same as when calculating the confidence limits of the random error. 5.6. Methods for processing the direct measurements results The main provisions of the methods of processing the direct measurements results with multiple observations are defined in GOST 8.207-76. The arithmetic average of n observations is taken as the measurement result, from which the systematic errors are excluded. It is assumed that the results of observations after exclusion of the systematic errors belong to the normal distribution. To calculate the measurement result, it is necessary to exclude a systematic error from each observation and to obtain a corrected result of the i-th observation as a result. Then the arithmetic average of these corrected results is calculated, which is taken as the measurement result. The arithmetic aver-

Chapter 5. Measurement errors

age is a consistent, unbiased and effective estimate of the measured value with a normal distribution of observational data. It is worth noting that sometimes in the literature, instead of the term “observation result”, the term “result of an individual measurement” is used, from which systematic errors are excluded. In this case, the arithmetic average value means the measurement result in this series of several measurements. This does not change the essence of the results processing procedures outlined below. In statistical processing of the groups of observations, the following operations should be performed: Exclude the known systematic error from each observation and get the corrected result of a separate observation x. Calculate the arithmetic average of the corrected observations taken as the measurement result: n

∑x

x=

i =1

i

n

.

Calculate the estimated standard deviation group: n

S=

∑ (x i =1

i

− x)2

(n − 1)

of the observation

.

Check for gross errors if there any values (xi – x), that are beyond ±3S. Under the normal distribution law, with a probability almost equal to 1 (0.997), none of the values of this difference should go beyond the specified limits. If there are any, the corresponding values should be excluded from consideration of the xi value and the x calculations and the S evaluation should be repeated. Calculate the sigma estimate S (x ) of the measurement result (arithmetic average) n

S(x) =

∑ (x i =1

i

− x)2

n(n − 1)

.

63

64

Section 1. Metrology as the science of measurement

Check the hypothesis about the normal distribution of the results of observations. There are various approximate methods for checking the normality of the distribution of observations results. Some of them are given in GOST 8.207-76. When the number of observations is less than 15, in accordance with this GOST, their belonging to the normal distribution is not checked. Confidence limits of the random error are determined only if it is known in advance that the results of observations belong to this distribution. Approximately the nature of the distribution can be judged by constructing a histogram of the results of observations. Mathematical methods for checking the normality of the distribution are discussed in the special literature. To calculate the confidence limit ε of the random error (random error component) of the measurement result, we use the formula

ε = t q S (x ) , where tq is Student’s coefficient depending on the number of observations and the confidence level. For example, with n = 14, P = 0.95, tq = 2.16. The values of this coefficient are given in the appendix to the given standard. Calculate the limits of the total non-excluded systematic error (NSE) of the measurement result Θ (according to the formulas in Section 4.6). Analyze the ratio of Θ and S (x ) : If

Q 〈 0,8 S( x )

, then the NRE is neglected compared to the random Q S (x )

errors, and the margin of error of the result is ∆ = ε. If > 8, then the random error can be neglected and the error bound of the result is ∆ = Θ. If both inequalities are not satisfied, the bound error of the result is found by constructing a composition of the random errors distributions and the NSE using the formula: ∆ = KS∑, where К is the coefficient depending on the ratio of the random error and the NSE; S∑ is the evaluation of the total standard deviation of the measurement result. Estimation of the total standard deviation is calculated by the formula:

Chapter 5. Measurement errors

S Σ = 1 / 3 ⋅ ∑θ i + S 2 ( x ). 2

The coefficient K is calculated by the empirical formula: K=

ε +Q S ( x ) + 1 / 3 ⋅ (∑ Q 2 i )

.

i

Confidence probability for the calculation of and should be the same. The error from the use of the latter formula for composition of uniform (for NSE) and normal (for random error) distributions reaches 12% with a confidence level of 0.99. 9. Record the measurement result. Recording the measurement result is provided in two versions, since it is necessary to distinguish between measurements with the final goal of obtaining the value of the measured quantity and measurements, the results of which will be used for further calculations or analysis. In the first case, it is sufficient to know the total error of the measurement result and, with a symmetric confidence error, the measurement results are in the form: x ± ∆, P, where x is the measurement result. In the second case, the characteristics of the measurement error components should be known – the estimate of the standard deviation of the measurement result S (x ) , the NSE boundary Θ, the n number of observations made. In the absence of the data on the form of the distribution functions of the error components of the result and the need for further processing of the results or error analysis, the measurement results are presented in the form:

S (x ;) S (x ). n, Θ. If the boundaries of the NSE are calculated in accordance with Clause 4.6, then additionally indicate the confidence probability P. Estimates S (x ) , Θ and derivatives of their values can be expressed both in the absolute form, i.e. in units of the measured quantity, and relative form, i.e. as the ratio of the absolute value of this quantity to

65

66

Section 1. Metrology as the science of measurement

the result of measurement. In this case, calculations using the formulas of this Section should be carried out using the quantities expressed only in absolute or relative form. Test questions to the module 1. What are the ways to reduce the systematic components of the error? 2. What parameters characterize the distribution law of random variables? 3. What laws of random variables distribution are most characteristic for measuring instruments and why? 4. What are the features of the random variables normal distribution? 5. What is the fundamental difference between a point estimate of a measurable quantity and an estimate using the concept of a confidence interval of uncertainty? 6. What is the purpose of checking the normal distribution of the results of observations? 7. What ways are used to detect the presence of systematic errors in the measurement results? 8. What errors are considered gross? 9. What ways can be used to reduce random and systematic errors? 10. What is the difference between equal and non-equal measurements? 11. What is the criterion of insignificance of errors? 12. What are the features of summation of various measurement errors components?

Chapter 6

GENERAL INFORMATION ABOUT ELECTRICAL MEASUREMENTS AND CLASSIFICATION OF MEASURING INSTRUMENTS

6.1. Types of electrical measurements The task of electrical measurements is to find the values of physical quantities empirically using special electrical means and the expression of these values in accepted units. Generally speaking, the quantity unit may have any dimension. However, measurements must be made in generally accepted units. Such units are established in each country by special legislation considering the recommendations of international organizations. Means of electrical measurements are the technical means used in electrical measurements with normalized metrological characteristics. There are the following types of means of electrical measurements: Measures are called measuring instruments designed to reproduce the physical quantity of a given size. There are fixed measures, multi-value measures and sets 67

68

Section 1. Metrology as the science of measurement

of measures. A fixed measure reproduces a physical quantity of the same size; a multi-value measure reproduces a series of similar values of different sizes. An example of multi-value measures is a variable capacitor. A set of measures is a specially selected set of measures applied not only separately but also in various combinations to reproduce several similar quantities of various sizes. Examples of a set of measures are resistance boxes, containers, etc. Electric measuring instruments are instruments for electrical measuring designed to produce signals of measuring information, i.e. signals functionally related to the measured physical quantities in a form available for direct perception by the observer. By the types of the measured quantity the devices are divided into ammeters – for measuring current; voltmeters – for measuring voltage; ohmmeters – for measuring resistance, etc. Measuring transducers are the means of electrical measurements designed to generate a signal of measurement information in a form convenient for transmission, further conversion, processing and storage, but not amenable to direct perception by the observer. Depending on the type of measured quantities, the measuring transducers are divided into two groups: 1) converters of electrical quantities into electrical quantities; 2) converters of non-electrical quantities into electrical quantities. The shunts, voltage dividers, measure transformers and other devices are converters of electrical quantities into the electrical ones. The use of transducers allows us to manufacture instruments for different limits of measurement, to measure relatively large currents and voltages with instruments that have smaller limits of measurement, etc. Examples of such converters are: converters of measured electrical quantities into a code that can be used to transmit the measurement information via communication channels or loaded into electronic computers for subsequent processing according to a given program or to represent the measurement information in digital form. Transducers of non-electrical quantities into electrical ones are: a vast group of transducers used in electrical measurements of nonelectrical quantities. Examples are: various thermistors, inductive

Chapter 6. General information about electrical measurements and classification ...

converters, with which a measured non-electric quantity (temperature, pressure, etc.) is displayed as an electrical quantity (electrical resistance, inductance, etc.) that is in a certain functional dependence on the measured non-electrical quantity. An electrical measuring device is a set of functionally and structurally combined measuring instruments and auxiliary devices intended for rational organization of measurements. The measurement setup allows us to pre-define a specific measurement method and estimate the measurement errors in advance. Measuring information systems (MIS) are a set of measuring instruments and auxiliary devices intended for automatic collection of measurement information from a number of sources with multiple (e.g. sequential) use of the same signal converters carrying the measurement information, transmitting measuring information to other distances through communication channels and its presentation in one form or another. A communication channel means a set of technical instruments ensuring the transfer of information from the information transmitter to the receiver. Based on the definition of MIS, their main differences from other measuring instruments are the automatic collection of measurement information from a number of sources and the repeated use of signal converters. The tasks performed by the MIS can also be solved by using other types of measuring instruments, e.g. measuring instruments that are individual for each measured quantity. However, the use of the same measuring transducers in a number of MIS channels, as compared to solving a problem by means of instruments, provides significant technical and economic advantages of MIS, which is especially important with a significant number of measured values. MIS can be divided into two groups: 1. Measuring systems – systems designed to perform the above functions with presentation of measurement information in a form suitable for observation or recording. 2. Automatic control systems (control and measuring systems) – systems designed to obtain information on deviations of monitored

69

70

Section 1. Metrology as the science of measurement

values from the nominal values. For example, the deviations of the temperature of different points of an object from the given values. 6.2. Measurement of electrical signal parameters 6.2.1. Voltage measurement With this type of measurement, a circuit with an additional resistor is used. It is carried out in the frequency range of 0-109 Hz (at higher frequencies, the voltage ceases to be an informative parameter). DC voltage from fractions of millivolts to hundreds of volts is often measured by magnetoelectric voltmeters (accuracy class up to 0.05). The main disadvantage is low input resistance, determined by the value of additional resistance (tens of kOhm).

Figure 7. A voltage measurement circuit with an additional resistor

Electronic analogue voltmeters are free from this drawback. Their output resistance is tens of kOhms. They can measure resistances from μV units to several kV. The main sources of error are: instability of the elements and the intrinsic noise of electronic circuits. The accuracy class of such devices is up to 1.5. Both magnetoelectric and electronic voltmeters have a temperature error, as well as mechanical errors of the measuring mechanism and scale errors. Precise DC voltage measurements are made using DC compensators. Their measurement accuracy reaches 0.0005%. The rms (effective) AC value is measured by electromagnetic (up to 1-2 kHz), electrodynamic (up to 2-3 kHz), ferrodynamic (up to 1-2 kHz), elec-

Chapter 6. General information about electrical measurements and classification ...

trostatic (up to 10 MHz) and thermoelectric (up to 100 MHz) devices. The difference in the shape of the measured voltage from the sinusoidal can sometimes lead to large errors. The most convenient devices in operation are digital voltmeters. They can measure both constant and alternating voltages. Their accuracy class is up to 0.001, the range is from microvolts to several kilovolts. Modern microprocessor DVs are equipped with a keyboard and often allow measurements not only of voltage, but also of current, resistance, etc., i.e. they are multifunctional measuring devices – testers (multimeters). 6.2.2. Purpose and classification of electronic voltmeters. Electronic voltmeters make up the most extensive subgroup among electronic devices. In accordance with the purpose, the devices of this subgroup are divided into voltmeters of direct, alternating and pulsed current, phase-sensitive selective and universal voltmeters, ratio and voltage difference meters, voltage converters. A distinctive feature of direct current EVs is their high input resistance, due to which these devices are suitable for measuring voltages in circuits with resistance up to several MOhm. EVs for AC alternating current are designed to measure voltages in the frequency range from several Hz to several thousand MHz. Pulse voltmeters are used to measure the amplitude of the AC voltage, as well as to measure single or repetitive voltage pulses. Selective voltmeters are electronic voltmeters with selective and tuning devices at the input. They are used to measure the high-frequency voltages with the presence of interference. In universal voltmeters, in addition to measuring voltage, measurement of direct current, resistance to direct current, and frequency is provided. Using voltage ratio meters, it is possible to determine the ratio of two DC or AC voltages. Voltage converters are used to convert the voltage of one type to another. Characteristics of radio engineering measurements determine the following requirements for the EV: wide limits of measured voltages,

71

72

Section 1. Metrology as the science of measurement

large frequency range, high input resistance, small reactive input resistances, small measurement error. DC electronic voltmeters. An electronic DC voltmeter contains an input resistive voltage divider, a DC amplifier, a meter (usually a magneto-electrical system) and a power supply. Figure 8 presents its structural diagram. A significant problem is the drift of the DC amplifier, which, with the presence of a measured voltage, is inseparable from the useful signal and introduces an error. To obtain a high input resistance, the DC amplifier of electronic voltmeters is performed on electron tubes or field-effect transistors. To reduce the zero drift in the DC amplifier of electronic voltmeters, balanced circuits and signal modulation are used. Modulation of the signal is used in voltmeters designed to measure small voltages (0.1 V and less), which allows us to reduce the zero drift of the DC amplifier to a fraction of a volt in several hours of operation.

Figure 8. Block diagram of an electronic DC voltmeter

AC electronic voltmeters. The structural diagram of this type of voltmeter, in addition to the above elements, contains an AC-DC converter to a permanent detector (rectifier). Depending on the type of the detector, the reading of a voltmeter can be proportional to the average, amplitude or root-meansquare value of the measured voltage. According to the structural scheme, electronic voltmeters of alternating voltage are divided into two main types: detector-amplifier and amplifier-detector. The devices of the first type are universal and allow us to measure both AC and DC

Chapter 6. General information about electrical measurements and classification ...

voltage, characterized by a wide frequency range (up to 1 GHz). Their drawback is a relatively low sensitivity. These devices are based on an electronic DC voltmeter, which is complemented by a special remote node – the probe containing the detector. A constant component of the rectified voltage detector is connected to the input of the device via a cable. The detector is performed on microwave vacuum and semiconductor diodes and emits a peak (amplitude) voltage value. Such detectors may have an open or a closed input. In a circuit with an open input (Fig. 9a) on a capacitor C, after several half periods of positive voltage, a voltage value close to the peak voltage is set. In the diagram (Fig. 9b), capacitor C is charged during the negative half-cycle of the measured voltage. When measuring pulsating voltage, voltmeters with detectors of various types will give different readings. The readings of the voltmeter with a closed type detector will not depend on the DC component. Such voltmeters are widely used (for example, V7-17). Voltmeter V7-17 is designed to measure a constant, root-mean-square value of harmonic voltages and active resistance. Amplifier-detector type voltmeters are characterized by a narrower operating frequency range (up to 30 MHz), limited by the amplifier bandwidth. The lower limit of the measured voltage is determined by the level of the intrinsic noise of the amplifier and is usually several microvolts. These devices are electronic microvoltmeters of alternating current. The input voltage dividers are used to extend the range of measured voltages.

a)

b)

Figure 9. Peak diode detector circuits: a) with an open input; b) with a closed input

73

74

Section 1. Metrology as the science of measurement

Amplification properties of millivoltmeters must remain constant in a wide frequency band while supply voltage, temperature and parameters of circuit elements change in certain limits. Diode detectors of medium-voltage are conventional single and full-wave rectifiers. Effective detectors include a system with a thermoelectric converter. Pulse voltmeters are designed to measure pulses of any polarity in a wide range of durations and frequencies of sinusoidal signals. According to the principle of operation, pulse voltmeters are devices of the detector-amplifier or amplifier-detector type. Such devices for reducing the error in measuring pulses of high duty ratio are equipped with devices for artificial expansion of pulses – auto-compensation circuits. Auto-compensation devices have high sensitivity, which allows using them as millivoltmeters of pulse current. 6.2.3. Current measurement The shunt is used to extend the current measurement limit of the measuring device of the magnetoelectric system and is a resistor Rsh connected to the measuring current circuit, in parallel with which the device is switched on. To eliminate the influence of resistances of contact connections, the shunts are supplied with current and potential clamps. Thus, the shunt is a four clamping device. Two input terminals, to which the measured current is supplied, are called current, and two output terminals, from which the voltage U is taken, are potential. The shunt is characterized by the rated output voltage. Their ratio determines the nominal value of shunt resistance: Rsh = Unom/Inom. In the presence of a shunt, the current Iin flowing through the measuring mechanism is linked with the dependence measured by the current Iin = I·Rsh /(Rsh + Rin), where Rin is the resistance of the measuring mechanism. If it is necessary for the current Iin to be n times less than the current I, then the shunt resistance should be Rsh = Rin/(n-1). The param-

Chapter 6. General information about electrical measurements and classification ...

eter n=I/Iin is called the shunting coefficient. As a result of expansion of the measurement limit of the device due to the shunt, the division value of its scale changes, which should be taken into account when reading the current values on the scale. Portable devices are often supplied with multi-range shunts consisting of several resistors, switched in a certain sequence depending on the limit of measurement. The diagram (Fig. 10a) shows a current meter for three measurement limits. Each of the resistors is used as a shunt for only one measurement limit. Such shunts are calculated by the formulas: R1 = Rvt / (n1 – 1); R2 = Rvt / (n2 – 1); R3= Rvt / (n3 -1), where n1; n2; n3 are shunting factors in the measurement range I1; I2; I3.

a)

b)

Figure 10. Multi-range milliammeter circuits: a) with single shunts; b) with a universal shunt

The use of a shunt causes: a) an increase in power consumption; b) reduction in measurement accuracy and sensitivity. Shunts are used mainly in DC circuits, as in alternating current circuits the frequency and inductance of the elements affect. Additional resistors, their purpose and calculation Additional resistors are used to extend the range of voltage measurement and reduce the effect of temperature on the resistance of a voltmeter. Precise small-sized manganic wire resistors, as well as non-

75

76

Section 1. Metrology as the science of measurement

wire resistors of increased stability (precision and high-precision), which have a minimum temperature coefficient of resistance in the working temperature range, are used as additional resistors As a result of switching on the additional resistor, the input resistance of the voltmeter increases significantly and becomes equal to RВТ + RД. The resistance of the additional resistor RД = RВТ (m-1), where m is a number indicating how many times the measurement limit of the voltmeter must be increased. As a result of the inclusion of RД, the division value of the voltmeter increases, which must be considered when reading the meter. Also the input resistance increases. For the convenience of comparing the multi-limit voltmeters and evaluating their effect on the circuit mode, the value of the relative input resistance Rinp is used, which is numerically equal to the resistance attributable to the 1V limit value. This resistance can be defined as Rinp = 1 / In0. 6.2.4. Power measurement It is carried out in DC and AC circuits using electrodynamic and ferrodynamic wattmeters. Change of limits is achieved by switching sections of the current coil and connecting of various additional resistors. Frequency range: from 0 to 2-3 kHz. Accuracy class: 0.1 – 0.5 for electrodynamic and 1.5 – 2.5 for ferromagnetic ones. Power can also be measured indirectly using an ammeter and a voltmeter, with multiplication of the results. The effect of digital wattmeters is based on the same principle. 6.2.5. Electrical energy measurement For this purpose induction measuring devices are mainly used. In recent years, in a wide use are digital energy meters based on the principle of an ammeter-voltmeter, where the result of multiplication is integrated over time.

Chapter 6. General information about electrical measurements and classification ...

6.2.6. Measurement of electrical circuit parameters Measurement bridges. Single DC bridges are designed to measure resistances of 10 Ohms or more. A single bridge scheme is shown in Fig. 11:

Figure 11. Single bridge scheme

The diagonal indicated in Fig. 11 as «bd» is called the power supply diagonal. It includes a power source (battery) G. The «ac» diagonal is called the measuring diagonal. It includes an equilibrium pointer (galvanometer) R. The equilibrium condition of the bridge: R1R3= R2R4. Double DC bridges, as shown in Figure 12, are used for accurate measurements of resistances of small magnitude.

Figure 12. Double bridge scheme

77

78

Section 1. Metrology as the science of measurement

During measurement, the measured resistance Rx is compared with the reference resistance R0. The resistance of an unknown resistor in case of the bridge equilibrium can be expressed as follows: R x = R0

R R1 = R0 3 . R2 R4

Double bridges allow us to measure the resistance in the range of 10-8…1010 Ohms. AC bridges are used to measure both active and reactive impedances (capacitive and inductive). In this case, reactive elements such as capacitances and inductances can be used as bridge elements. Equilibrium equations are written similar to the DC bridges. In recent years, automatic bridges and compensators are often used to measure the parameters of electrical circuits, where the process of bridge balancing occurs automatically (using a reversing motor or electronic circuit). The use of automatic bridges in high-precision digital measuring devices is especially important. 6.2.7. Resistance measurement Resistance to direct current is measured by direct evaluation devices – ohmmeters and bridges. Ohmmeters are most often made based on a magnetoelectric mechanism. The measurement range of ohmmeters is from ten thousandths of Ohms to hundreds of MOhms. The measurement error of ohmmeters is usually from 1 to several percent, but increases sharply at the edges of the scale. Recently, digital multi-limiting ohmmeters, most commonly included in universal digital measuring instruments, have become widespread. Most accurately resistance can be measured using DC bridges. 6.2.8. Capacitance and inductance measurement It is mainly fulfilled with AC bridges with supply frequencies of 100-1000 Hz. Most often, bridges for measuring resistance, capaci-

Chapter 6. General information about electrical measurements and classification ...

tance and inductance are combined in one device – a universal measuring bridge. Such devices can measure the inductance from fractions of μH to thousands of Henry, and the capacity – from hundredths of picofarads to thousands of microfarads. The error of universal bridges usually does not exceed hundredths of a percent [1]. 6.3. Standards, reference and working measures A standard for a unit of a physical quantity is a measurement unit (or a set of measurement instruments) providing reproduction and (or) storage of a unit in order to transfer its size to the measurement tools located below in a calibration scheme. Depending on the accuracy of reproduction of units of measurement and purpose, the standards of units are divided into the following groups: A primary standard – a standard that provides reproduction of the unit with the highest accuracy in the country; A secondary standard – a standard, the value of which is established by the primary standard; A state standard – a primary or a special standard approved for the country as a reference; A working standard – a standard used to transfer the size of a unit to exemplary measuring instruments of higher accuracy, and in some cases to the most accurate working measuring instruments.

79

Section 2

STANDARDIZATION

Chapter 1

CONCEPTS AND DEFINITIONS

1.1. Purpose of standardization Standardization is the activity on establishing the rules and characteristics for the purpose of their voluntary multiple use aimed at achieving orderliness in production and circulation of products and improving the competitiveness of products, works and services. Standardization activity is very dynamic, it extends to the most diverse areas of activities and serves both to increase their efficiency and to achieve higher competitiveness in the domestic and foreign markets and mutual understanding with foreign partners and counterparties. The role of standardization in the economic sector is especially important; it should not only correspond to the changes occurring there, but also be ahead of them, so the standards could promote the development of production, rather than restrain it. Standardization activities occur during the development, publication and application of standards. The work in standardization is regulated by the Law of the Republic of Kazakhstan “On Technical Regulation” and the state standardization system. 82

Chapter 1. Concepts and definitions

The main factor in determining the legal status of standardization activities is the voluntary nature of the application of national standards. Standardization is carried out to: – increase the safety level of life and health of citizens, animals and plants, property, environmental safety, security and promote compliance with the requirements of technical regulations; – increase the level of safety of facilities considering the risk of emergency situations of natural and man-made character; – ensure scientific and technical progress, rational use of resources, realization of government orders, confirmation of conformity of products (works, services), delivery, judicial decisions; – increase competitiveness of products, works and services; – provide technical and information compatibility; – provide comparability of research and measurement results; – provide product interchangeability; – create systems for classifying and coding of technical, economic and social information, product cataloging systems, product quality assurance systems, data retrieval and transmission systems; – facilitate unification work. One of the goals of the standardization development in Kazakhstan is to increase the transparency of the State Standardization System (SSS), which is one of the requirements of the World Trade Organization (WTO) membership. To enter the WTO, a complete harmonization of the foreign economic activity regulation methods with the rules of this organization is required. In standardization, this is bringing the SSS regulatory documents into conformity with the Standards Code’s requirements, the main requirement of which is that the standardization regulatory document does not become a technical barrier to trade. An example of the standardization development in Kazakhstan in modern conditions is the adoption of the law on technical regulation discussed above, which introduces a new mandatory regulatory document – technical regulation.

83

84

Section 2. Standardization

1.2. Principles of standardization – voluntary application of standards; – maximum consideration of interests of the parties concerned; – application of the international standard as the basis for the national standard development; – inadmissibility of creating obstacles to production and circulation of products; – inadmissibility of setting the standards contradicting the technical regulations; – creation of conditions for uniform application of standards. It should be noted that, despite the voluntary nature of the standards application, the work on standardization is the function of the state and is regulated by the state represented by an authorized body of the Republic of Kazakhstan. Openness of national standards development processes should be ensured at all stages, from planning to standard adoption. National standards should be approved in the absence of serious objections on substantive issues by a qualified majority of the parties, i.e. with a general agreement (consensus). 1.3. Organization of work on standardization The work on standardization is organized by the authorized body for standardization of the Republic of Kazakhstan. These functions are assigned by the Government of the Republic of Kazakhstan to the Technical Regulation and Metrology Committee, which is currently a part of the Ministry for Investment and Development of the Republic of Kazakhstan. The structure of the Committee includes the Department of Technical Regulation, the Department of State Control Monitoring and Analysis, the Department of Economics, Finance and Public Procurement, the Department of Metrology and Conformity Assessment, RSE KazInSt, RSE KazInMetr, NCA LLP, Coordinator LLP, 14 territorial departments of the Committee. The Unified State

Chapter 1. Concepts and definitions

Fund of regulatory and technical documentation currently has 68,008 regulatory and technical documents, including 5,725 national standards of the Republic of Kazakhstan, 16,081 standards of the International Organization for Standardization, 22,695 interstate standards. Functions of the national standardization body: – approval of national standards; – adoption of a program for standard developing; – organization of the draft standard examination; – consideration of national standards and other standardization documents; – establishment of technical committees for standardization and coordination of their activities; – presentation of the Republic of Kazakhstan in international standard organizations. Organization and development of national standards, their coordination and expertise are carried out by technical committees on standardization. The direct standard developers can be any person or a working group consisting of representatives of parties concerned. Representatives of federal executive bodies, scientific organizations, public associations of entrepreneurs and consumers, self-regulating organizations may be the members of technical committees on standardization on a parity basis. The scientific and technical base of the TCs is usually maintained by enterprises or organizations whose activities correspond to the technical committee’s specialization. TCs are permanent working bodies for standardization. 1.4. Documents in standardization Rules, norms and requirements are developed during the work on standardization for various standardization objects, which are drawn up in the form of various regulatory documents (RD). The main type of documents is the standard. Standard is a document establishing the product characteristics, rules for its implementation and characteristics of production process-

85

86

Section 2. Standardization

es, performance of works or provision of services for the purpose of voluntary multiple use. The standard may also contain requirements to terminology, symbols, packaging, labeling or labels and the rules for their application. Documents in standardization used in the Republic of Kazakhstan include: – national standards; – national military standards; – intergovernmental standards introduced in the Republic of Kazakhstan; – rules of standardization, norms and recommendations in standardization; – All-Russian classifiers of technical, economic and social information used in the established order; – standards of organizations. The term “national standard”, in contrast to the previously used “state standard”, reflects its non-state (non-mandatory) status, but indicates the possibility of its application on the territory of the Republic of Kazakhstan. The national standard is applied voluntarily, after which all its requirements become mandatory for observance. This follows from the fact that the Law formulating the standardization principles indicates the voluntary application of standards, leaving aside the voluntary application of other documents in standardization. Hence it means that once a decision has been made to apply the standard, the rules for its use become mandatory. Otherwise, all work on the standards application is disorganized. But in case of violation of the standardization rules, no measure of liability to the state can be established and applied. The designation of the national standard consists of the index “GOST R”, the registration number and the four digits of the year of approval (adoption) of the standard separated from it. For example, GOST R-2000. Registration numbers are assigned to the newly developed standards in ascending order of numbers as they are registered. When a standard is canceled, its number is not assigned to another

Chapter 1. Concepts and definitions

standard, except for its revision or adoption instead of another standard. If several standards have a common object of standardization, they are assigned with a common registration number and an additional number separated from it by a dot for each individual standard. In this case, the standard establishing general (basic) requirements is assigned a zero additional number (see the example at the beginning of Section 3). If the standard is included in the system of general technical or organizational and methodical national standards of the Republic of Kazakhstan, the standard designation includes a one-digit or a twodigit code of the standards system separated by a dot from the rest of the digital part of the designation. For example, metrology standards have code 8: GOST R 8.417-2002 “GSI. Units of quantities” or GOST R 22.10.01-2001. The following data are given on the title page of the standard: the full name of the authorized body of the Republic of Kazakhstan on standardization and its logo, the designation of the standard, its status in the “State Standard of the Republic of Kazakhstan”, the name of the standard and information about the publisher. National standards and classifiers, including the rules for their development and application are the national standardization system. Rules (Rl) and recommendations (R) on standardization relate to regulatory documents of a methodological nature and may refer to the order of coordination of the regulatory documents, creation of standardization services at enterprises and other issues of organizational nature. All-Russian classifiers are the regulatory documents distributing technical, economic and social information in accordance with their classification (classes, groups, types, etc.) and are mandatory for use in creating state information systems and resources. The order of their development, adoption for entering into force, maintenance and application is established by the Government of the Republic of Kazakhstan Due to the development of information technologies, the methods of information classification and coding have become especially

87

88

Section 2. Standardization

important. Market relations in the economy require substantial modernization of the classifiers operating in Kazakhstan till now and creation of new ones. All-Russian classifiers should both solve the problems of consistency of interdepartmental information flows and ensure comparability of classifiers of various federal authorities and international organizations. The Unified System for Classification and Coding of Technical, Economic and Social Information (USCC) is being created in Kazakhstan, the components of which are the All-Russian classifiers, their means of control, regulatory and methodological documents on their development, maintenance and application. The classification objects are: statistical information, macroeconomic financial and law enforcement activity, banking activity, standardization, production, provision of services, etc. The main purpose of classifications is to ensure information compatibility in all areas of activity. More than 20 All-Russian classifiers are used in Kazakhstan. For example, the All-Russian Classifier of Standards (ACS), which is based on the direct application of the International Classifier of ISO Standards. National standards and All-Russian classifiers of technical, economic and social information, including the rules for their development and application, constitute the national standardization system. Standards of organizations, including commercial, scientific, public and others can be developed and approved independently based on the need to apply them: for standardization purposes (see above), to improve production and ensure the product quality, perform work and provide services, use the results obtained, measurements and developments. Standards of organizations are mandatory only for employees of these organizations. The procedure for developing, approving, recording and canceling the standards of organizations is established by them individually. The draft organization standard may be submitted by the developer in the TC on standardization to examine the project.

Chapter 1. Concepts and definitions

Standards of organizations are not elements of the national standardization system. 1.5. Types of standards Depending on the object and aspect of standardization, as well as the content of the requirements, the following types of standards are developed: – product standards; – standards for the processes of production, operation, etc.; – service standards; – fundamental standards (organizational, methodological and general technical); – standards for terms and definitions; – standards for control methods (tests, measurements, analysis). Fundamental standards establish general organizational and methodological provisions for a certain activity, as well as general technical requirements (norms and rules), ensuring: – mutual understanding, compatibility and interchangeability; – technical unity and interrelation of various areas of science, technology and production during creation and use of products; – environmental protection; – safety of public health and property and other general technical requirements ensuring interests of the national economy and safety. 1.6. International standardization The main international organizations involved in international standardization are ISO and IEC. 1. International Standardization Organization (ISO) ISO was founded in 1946, the abbreviation is used from the Greek “isos” – equal, which sounds the same in all languages. ISO deals

89

90

Section 2. Standardization

with standardization in all areas except electrical engineering and electronics. ISO includes 120 countries, Russia is represented by the State Standard Committee of the Republic of Kazakhstan as a member committee of ISO. The organization consists of the management and working bodies. Managing bodies: General Assembly, Board, Technical Management Bureau. Working bodies – Technical Committees (TC), Subcommittees (SC), Technical Advisory Groups (TAG). Currently, international standardization within ISO is carried out by more than 2,800 working bodies, including 185 TCs, 640 SCs. 10 TCs and 31 SCs are assigned to Russia. ISO goals are to promote the development of standardization and related activities to ensure the international exchange of goods and services, as well as the development of cooperation in intellectual, scientific-technical and economic sectors. Main objects of standardization: engineering, chemistry, ores and metals, information technology, construction, medicine and health care, environment, quality assurance systems. The result of the ISO work is the development and publication of international standards made by technical committees and working groups by activity types. There are more than 10 thousand ISO standards, 500-600 standards are adopted annually. They do not have the status of mandatory documents. More than half of ISO standards are applied in Kazakhstan. ISO standards are a thoroughly developed version of technical requirements for products (services), which greatly facilitate the exchange of goods, services and ideas between countries. ISO standards are not mandatory for all participating countries. Only about 20% of ISO standards include requirements for specific products. The bulk of

Chapter 1. Concepts and definitions

RD relates to safety requirements, interchangeability, technical compatibility, product testing methods. International Standardization Organization (ISO) National standards reflect the characteristics and level of scientific and technological development of the country where they are developed and applied. Therefore, the requirements of standards of different countries for homogeneous products often differ from each other, which is a serious obstacle to the development of international trade, as it necessitates the harmonization of product characteristics with the standards of the country that buys it. The development of international trade and international cooperation in all areas of human activity has objectively led to the need for coordination (harmonization) of national standards, development and wide application of international (regional) standards. Commencement of direct cooperation in standardization between various countries dates back to 1921, when the first conference of seven national standard committees was held. This conference developed organizational principles based on which the International Federation of National Standardization Associations (ISA) was founded in 1926, which included 20 national standards organizations. ISA had developed about 180 international standardization recommendations, but its activities were discontinued with the onset of the Second World War. The International Standardization Organization, being the world federation of national standards bodies, was established in London by the UN decision in 1947 by 25 national standards organizations. When choosing its name, it was decided to use a derivative of the Greek word “isos” – “equal”. That is why the International Standardization Organization has the short name ISO in all languages of the world. The activity of this non-governmental organization covers standardization in all areas, except electrical engineering and electronics, which are within the competence of the International Electrotechnical Commission (IEC). In addition to standardization, ISO deals with certification issues.

91

92

Section 2. Standardization

The main task of ISO is to stimulate the development of standardization and related activities throughout the world to facilitate the international exchange of goods and services and develop cooperation in intellectual property, scientific, technical, technological and economic activities. The practical result of ISO activities are international agreements achieved through the development, adoption and publication of international standards in various areas of activity. During their development, ISO considers the expectations of all parties concerned – manufacturers of products (services), consumers, government, scientific and technological and public organizations. 146 countries of the world participate in ISO with their national standardization organizations, of which 94 countries are members of ISO, 37 are the correspondent members and 15 are subscribing members (data as of 2003). ISO members are entitled to participate in the work of any ISO Technical Committee, vote on draft standards, be elected to the ISO Board and be represented at meetings of the General Assembly. Correspondent members are not active in ISO, but are entitled to receive information on the standards being developed. Correspondent members are mainly organizations of the developing countries. The ISO subscribing members pay contributions and have the opportunity to be aware of international standardization. The “subscribing members” category is for the developing countries. – The Republic of Kazakhstan represented by the Committee for Standardization, Metrology and Certification became a full member of ISO in 1994, having the right to vote when discussing and making decisions on all issues. National standardization organizations are the guides of the ISO achievements in their countries, as well as representatives of the national point of view in the relevant technical committees of the organization. Besides, strong national standards organizations – ISO members support the ISO functioning. ISO cash funds are made up of contributions from member countries:

Chapter 1. Concepts and definitions

– funds from the sale of standards and other publications and donations. The organizational structure of the ISO consists of the managing and working bodies. Central Secretariat Technical committees Subcommittees Working groups The management bodies include the General Assembly, the ISO Board and its committees, the working bodies – technical committees (TC), subcommittees (SC) and technical advisory groups (TAG). The supreme ISO body is the General Assembly – a meeting of officials and delegates appointed by the members. Each member has the right to represent no more than three delegates. Correspondent members and subscribing members participate as observers. In between sessions of the General Assembly, the work of the ISO is done by the ISO Board headed by the ISO President. The Board consists of 18 members – representatives of national standardization organizations elected for three years, and has the right to send issues to ISO members for consultation or delegate their decisions to members without convening the General Assembly. At Board meetings, decisions are made by the majority of votes among those present. Between meetings and, if necessary, the Board may decide by census. An executive bureau has been established at the council that leads the ISO technical committees. Seven committees report to the ISO Board: PLACO (Technical Management Bureau), STACO (Committee for the Study of Standardization Scientific Principles). CASCO (Conformity Assessment Committee), INFCO (Information Systems and Services Committee), DEVCO (Developing Countries Assistance Committee), COPOLCO (Consumer Protection Committee), REMCO (Standard Sample Committee). PLACO prepares proposals for planning the ISO work, organizing and coordinating the technical aspects of work. The scope of

93

94

Section 2. Standardization

PLACO work includes consideration of proposals for establishment and dissolution of technical committees, outlining of standardization areas, which should be handled by technical committees. STACO provides methodological and informational assistance to the ISO Board on the international standards principles and methods. The Committee conducts a study of the basic standardization principles and preparation of recommendations for achieving the optimal results therein. STACO is also engaged in terminology and organization of seminars on application of international standards for the trade development. CASCO deals with issues of confirming the compliance of products, services, processes (works) and quality systems with the standards requirements. The Committee develops guidelines on testing and compliance assessment (certification) of products, services, processes (works), quality systems, confirmation of competence of testing laboratories and certification bodies, promotes mutual recognition and adoption of national and regional certification systems, as well as the use of international standards in testing and certification confirmation. INFCO provides scientific, methodological and practical management of information support for standardization based on the existing fund of standards and automated data banks, organizes the sale of standards and technical regulations. DEVCO examines the requirements of developing countries in standardization and develops recommendations to assist these countries therein, organizes a large-scale discussion of all aspects of standardization in the developing countries, prepares standardization specialists in the training centers in the developed countries, develops standardization training manuals for the developing countries, promotes the development of bilateral cooperation of the industrialized and developing countries in standardization. COPOLCO examines the issues of ensuring the consumer interests and the possibility of promoting them through standardization, summarizes the experience of consumer participation in creating standards and develops programs for educating consumers in standardization, organizes the distribution of necessary information about

Chapter 1. Concepts and definitions

international standards, prepares periodic publications of the list of international and national standards, prepares the guidelines useful for consumers; “Comparative testing of consumer goods”, “Information about consumer products”, “Development of standard methods for measuring the performance characteristics of consumer goods”, etc. REMCO is engaged in the development of relevant manuals on issues relating to reference materials (standards), their establishment and certification. In addition, REMCO is the focal point for ISO on standard samples with international metrology organizations, in particular, with the International Organization of Legal Metrology (OIML). The order for international standards development. The work on international standards development is carried out by Technical Committees (TCs) and Subcommittees (SCs) established by them and Working Groups (WGs) in specific areas of activity. As of the 2003 data, international standardization within ISO was carried out by 2,736 working bodies, including 186 TCs, 550 SCs and 2,000 WG. Technical Committees are divided into general technical committees and committees working in specific areas of technology. 26 general technical TCs solve general technical and intersectoral tasks. These include, for example, TC 3 “Tolerances and Fits”, TC 10 “Technical Drawings”, TC 12 “Units of Measurement”, TC 19 “Preferred numbers”, TC 37 “Terminology”. The other TCs operate in specific areas of technology (TC 22 “Cars”, TC 39 “Machine tools”, etc.). If the work carried out by the Technical Committee covers a wide range of issues, the Subcommittees are created within the Technical Committees. For example, TC 20 “Aircraft and spacecraft” includes ten Subcommittees. The order for international standard development is as follows. A party concerned in the international standard development represented by an ISO member, a Technical Committee or a Committee of the ISO Board (or an organization that is not an ISO member) submits an application to the ISO Board for the development of a standard. The Secretary General of the ISO Board submits a proposal for establishment of an appropriate TC to the Executive Bureau.

95

96

Section 2. Standardization

If the Executive Bureau is convinced of the international significance of the proposed standard, the majority of its members vote “for” and at least five of them intend to become members of the Working Group, then a Technical Committee for the standard development shall be established. All issues during the work are usually resolved based on the consensus of members actively involved in the TC activities. After reaching a consensus on the draft standard, the TC sends it to the Central Secretariat for circulation to all members to vote. In addition to the principle of consensus in voting on the draft international standard, ISO also ensures the mandatory transparency of the rules for developing standards understandable to all parties concerned. If the draft is approved by 75% of the members participating in the vote, it is published as an international standard. More than 40 thousand experts from 35 countries of the world participate in the ISO technical work. About 800 international standards are reviewed and adopted again annually. To date, more than 14 thousand ISO standards have been adopted. Standards developed in various sectors of technology are distributed as follows: engineering – 29.5%, chemistry – 3.4%, non-metal products – 12.2%, ores and metals -9.1%, information technology – 8.8%, agriculture – 8.5%, construction – 3%, special equipment – 3%, health and medicine – 3.3%, basic standards – 3.3%, environment – 3%, packaging and transportation of goods – 1.8%, etc. The current goal of ISO is to improve the structure of the standards fund. In the future, social areas and information technology should become a priority in the ISO activities. ISO standards are a thoroughly developed version of the technical requirements for products (services), which greatly facilitates the exchange of goods, services and ideas between all countries of the world. This is largely due to the responsible attitude of the Technical Committees to reaching a consensus on technical issues, for which the TC Chairmen are personally liable. In their content, ISO standards differ from national standards in that only about 20% of them include requirements for specific prod-

Chapter 1. Concepts and definitions

ucts. The main part of ISO standards concerns safety requirements, interchangeability, technical compatibility, product testing methods, as well as other general and methodological issues, i.e. those aspects without which the mutual understanding of the manufacturer and the consumer is not possible, regardless of the country where the products are manufactured and used. Thus, the use of most international ISO standards implies that specific technical requirements for a product are established directly in contracts. If applied, the ISO standard is introduced into the national standardization system of the country, and can also be applied in bilateral or multilateral trade relations. ISO international standards do not have the mandatory status for member countries, i.e. each country has the right to apply them entirely, in separate sections or not apply at all. The decision on their application is mainly related to the degree of the country’s participation in the international division of labor and the state of its foreign trade. However, in conditions of intense competition in the world market, manufacturers of products are forced to use the international standards seeking to maintain high competitiveness of their products. According to foreign experts, the industrialized countries (for example, the Netherlands, Sweden, Belgium, Austria, Denmark) use up to 80% of the total ISO standards fund. These countries tend not to establish the national standards in areas where the relevant international standards exist. The highest achievement for an ISO member state is the adoption of a national standard as an international one. To incorporate a national standard into an ISO work plan, an informing proposal must be submitted to the ISO Board indicating the role of the standard in expanding international trade, ensuring people’s safety and protecting the environment. Intense competition in the world market of countries and firms being the global manufacturers of specific products begins and manifests itself at the stage of developing an international standard, when ISO TC faces some pressure from representatives of individual countries about the technical requirements and standards that should be

97

98

Section 2. Standardization

included in the future international standard. Economically developed countries see the corresponding national standard in the draft of a specific international standard and struggle to reflect their national interests in this project. It is not by chance that more than 70% of the total number of international ISO standards correspond to national or company standards of industrialized countries. The leadership of a country in the development of international standards is largely determined by the degree of participation of its specialists in the activities of the ISO working bodies. In recent years, ISO has paid much attention to international standardization in services and quality assurance systems. To develop a uniform approach in addressing the issue of quality, TC 176 “Quality Management and Quality Assurance” was established, the task of which is to standardize and harmonize the fundamental principles of quality assurance systems. Based on the generalization of the national experience of the USA, France, Great Britain and other countries, the international standards of the ISO 9000 series and in the subsequent period of the ISO 14000 and ISO 17025 series were developed and published in 1987. ISO has established a strategic partnership with the WTO. All countries that are members of the WTO or plan to become ones should understand the issues of international standardization and be aware of their contribution to international trade. More than 100 countries out of the 146 ISO members are the developing countries and countries with economies in transition. Most of them do not have a developed infrastructure in standards and related sectors, such as technical regulations, conformity assessment, quality and metrology, which is a serious problem for participants in economic processes in these countries. As a result, excessive barriers to trade are created, resources and production capabilities are used inefficiently, leading to wasteful efforts to boost the economy and lower quality of life. It is for these reasons that ISO provides great assistance to the developing countries in improving standardization activities and creating the infrastructure of standards necessary for the economic development of the state and its integration into the world economy.

Chapter 2

SYSTEM APPROACH TO ENERGY MANAGEMENT

Energy management is a high-level practice for business management within the tough competitive conditions. The main goal of the energy management of the enterprise is the energy efficient and reliable operation of the organization’s energy system. Energy management, in contrast to the energy audit of the energy service, works continuously, increasing energy efficiency, competitiveness and attractiveness for investors. Since 2008, the International Standardization Organization (ISO), uniting 160 countries, has been developing the new international standard ISO 50001 “Energy Management Systems – Requirements”, which after the approval on June 15, 2011 has become the most innovative standard in energy management. ISO 50001:2011 provides the foundation for industrial enterprises, commercial facilities or entire organizations for energy management. Focusing on its widespread use beyond the national sectors of the economy, it is assumed that the standard will be able to affect more than 60% of the world’s energy consumption. Edwin Pinero, Chairman of the ISO/PC 242 Energy Management Project Committee, comments: 99

100

Section 2. Standardization

“Every day organizations around the world are dealing with issues such as access to energy, reliability, climate change, and depletion of resources. And how effectively the organization controls the use of its energy is the most important element in addressing these issues”. ISO 50001:2011 provides a robust management model that helps organizations systematically plan and manage their energy use. Aimed at performance and continuous improvement, ISO 50001:2011 shall contribute to the energy efficiency improvement. An extremely high degree of general consistency in this matter prompted our committee to rapidly approach the publication — hence confirming the fact that the world needs this standard.” The ISO/PC 242 Secretariat provides partnerships from ISO members: the United States (American National Institute of Standards – ANIS) and Brazil (Associaro Brasileira de Normas Técnicas – ABNT). Forty-three countries of ISO members and 12 countries as observers are involved in this development. The formally cooperating organizations included the United Nations Industrial Development Organization (UNIDO) and the World Energy Council (WEC). The document is based on the fundamental elements laid down in all management standards of the ISO series, which guarantees the highest level of compatibility with ISO 9001 (quality management) and ISO 14001 (environmental management). ISO 50001 shall provide the following benefits [1]: − Basis for integrating the energy efficiency into management practices. − More efficient use of existing energy-intensive assets. − Testing, measuring, documenting and reporting on energy intensity improvements, as well as their predicted impact on reducing greenhouse gas (GHG) emissions. − Transparency and interaction in the energy resources management. − Best practices and good governance in energy management systems. − Assessment and prioritization of introduction of new energysaving technologies.

Chapter 2. System approach to energy management − Basis

for energy efficiency throughout the supply chain. energy management in the context of greenhouse gas emission reduction projects. − Improving

Experience in implementation of ISO 50001 standard abroad [2]

The evidence that publications of the ISO 50001 standard have been awaited for a long time is the number of organizations around the world which claim to be the first in the country or industry to introduce the new international ISO standard for energy management. Some of them have already reported significant benefits and reduced energy costs due to the introduction of ISO 50001, including the energy and thermal energy management company Delta Electronics (China); leader in global energy management Schneider Electric (France); Dahanu Thermal Power Station (India); LCD TV manufacturer AU Optronics Corp (Taiwan); municipality of Bad Eisenkappel (Austria). These organizations report the benefits of introducing the ISO 50001 standard, including significant reductions in energy consumption, carbon dioxide emissions and energy consumption costs, as well as benefits for production sites, communities and the environment. Thus, Delta Electronics (China) shows that introduction of ISO 50001:2011 in the energy management system in the Dongguan

101

102

Section 2. Standardization

region allowed them to reduce electricity consumption by 10.51 million kilowatt-hour compared to the same period of 2010, along with constant production capacity from January to May of the same year. This is equivalent to reducing 10.2 thousand tons of carbon dioxide emissions and saving 8 million yuan (CNY). Schneider Electric (France) believes that the ISO 50001 international standard can be implemented at all sites and with all customers worldwide. It can also be easily integrated with other standards, such as ISO 14001. About 90% of the company’s sites in the world are certified in accordance with ISO 14001. Dahanu Power Station (India) has made a series of targeted investments since March 2010. With the new energy management system based on ISO 50001:2011, this investment is expected to save about 96.4 Indian Rupees (INR) per year by improving the efficiency and quality management. AU Optronics (Taiwan, Province of China) believes that the introduction of ISO 50001 will allow it to achieve 10% energy savings at the plant this year equal to 55 million kilowatt-hours of electricity, and reduce carbon emissions by 35,000 tons. Now the company plans to adopt the energy management system based on ISO 50001:2011 in all its industrial enterprises. The municipality of Bad Eisenkappel (Austria) expects that during the first year after the implementation of ISO 50001:2011, electricity consumption will be reduced by 25%, and the main savings to be achieved by updating the wastewater treatment plant and reducing energy consumption by 86,000 kilowatt-hours, which is EUR 16,000 in monetary value. Offers of energy audit companies are presented in [3]. A professionally conducted energy survey (energy audit) of an enterprise/organization provides answers to the following questions: gives objective data on the amount of energy resources used; determines the energy efficiency indicators; identifies potential energy savings and energy efficiency; develops a list of standard, publicly available measures on saving energy, increasing energy efficiency and carrying out their evaluation. The purpose of the energy audit is to assess the efficiency of using fuel and energy resources and to develop effective measures to reduce the costs of an enterprise.

Chapter 2. System approach to energy management

During the energy survey, tasks that consistently achieve the goal of an energy audit are identified: − Improvement of the reliability of power supply; improvement of the reliability and fire safety of power plants; energy efficiency increase; − optimization of organizational and economic aspects of the energy sector; environmental aspects of the energy complex; − making of Energy Passports of enterprises; preparation of substantiating materials on tariffs for production and transmission of heat and electricity. It is possible to resolve all tasks only with the joint work of highly qualified engineers and experts of the energy auditor with the operating personnel and the Customer’s specialists directly at the facilities of the enterprise. The Digital Group company offers an integrated system approach in energy saving: energy research (energy audit); introduction of an energy management system; development of an energy efficiency improvement program; phased implementation of the program (including the ideology of EPC); economic effect monitoring.

Possible actions of consumers of fuel and energy resources

103

104

Section 2. Standardization Fuel and energy resources reduction → reduction in consumption of fuel and energy resources

Energy saving is the implementation of measures aimed at reducing the amount of energy resources used. That is, measures aimed at reducing only the cost of the purchase and turnover of fuel and energy resources are not energy saving measures! (the issue is not within the scope of energy audit and energy saving). Examples of energy saving measures: – installation of metering devices for fuel and energy resources (heat energy, hot water); – installation of metering devices at the border of the balance sheet attribution; – transition to the tariff differentiated by day zones; – alignment of the load curve (increase in the CCIM); – transition to the other energy saling company; – transition to a higher level of voltage; – independent access to the wholesale electricity market; – assignment of the status of a grid (energy supplying) organization to receive funds from sub-subscribers for supply/compensation of fuel and energy resources loss; construction of one’s own generation facility/wells, etc.; transition to another (cheaper) type of fuel and energy resources; – use of treatment technologies, as well as organization of wastewater assessment. Implementation of the energy management standard in the organization (ISO 50001) will allow it to effectively manage the power units.

Chapter 2. System approach to energy management

Energy audit and energy service are only part of an enterprise or organization management system.

105

106

Section 2. Standardization

Implementation of ISO 50001:2011 standard in organizations. ISO 50001:2011 standard integrates with other standards: – ISO 9001 Quality Management Systems – ISO 14001 Environmental Management – OHSAS 18001 Occupational Health and Safety Management – ISO/IEC 27001 Information Security – ISO 28000 Supply Chain Security

Chapter 3

STANDARDIZATION AT THE ENTERPRISE

Proper use of standardization capabilities in the enterprise allows it to increase the efficiency of its functioning. The main components of the economic effect at a particular enterprise are: – reduction in the cost of standard products manufacturing; – increase in the sales price per unit of product due to an increase in its quality; – growth in sales of products as a result of increased demand for standard and higher-quality products; – reduction in the number of necessary funds of the enterprise (both basic and circulating) due to reduction in the production cycle duration and more intensive use of equipment in the production of standard products. According to experts, the cost price of engineering products is reduced by 10-15% due to standardization, and the cost of maintaining the factory standardization service is only 0.5% of the production cost. The scope of standardization work depends on: – production and cooperation scale; 107

108

Section 2. Standardization

– nomenclature and complexity of products, degree of novelty and intensity of change; – status of the enterprise standardization service and tasks assigned to it. The main tasks of the enterprise standardization service in the most general case are: – maintenance (storage and updating) of regulatory and technical documentation stock of an enterprise; – development of technical terms for the manufactured products; – examination and approval of draft regulatory and technical documents received by the company from the side; – development of necessary standards of the enterprise. Skillful use of standardization capabilities by managers of domestic enterprises can serve as a good prerequisite for creating more effective product quality management systems. If the work on standardization at an enterprise is directly aimed at improving the quality of products, the costs of their implementation are initially higher than the expected results. However, in the future, the consumer demand for higher quality products grows and it can be sold at much higher prices. Thus, the growth in sales revenues can not only compensate for the additional costs of an enterprise for quality improvement, but also provide a higher profit in the future compared to the one that products previously produced. If the work on standardization carried out at the enterprise does not change the quality of the products manufactured, the costs of their implementation overlap with the savings of raw materials, materials, time, labor and financial resources obtained within the enterprise. Thus, for example, as a result of unification of raw materials and materials, their standard sizes are reduced in the company’s stocks, the level of stocks themselves is reduced, the required storage areas are significantly reduced, the logistics is improved, the working capital is saved, its turnover is accelerated, etc. All this, in turn, has a positive effect on production costs and ensures the growth of the company’s profits.

Chapter 3. Standardization at the enterprise

Test questions to the module 1. Name the regulatory and legislative basis for standardization. 2. What is called standard and standardization? 3. What is the purpose of introducing the state standardization system and what standardization work does it regulate? 4. Name the main standards of the SSS. 5. Explain the main goals of the SSS. 6. Name the goals and objectives of standardization and explain them with examples. 7. Name the main tasks of the State Standard of Russia. 8. What international standards organizations do you know? 9. What are the main functions of the technical committees of the State Standard of Russia? 10. What do the regional standardization centers do? 11. What standardization services are established at enterprises? 12. What regulatory documents do standardization services develop at enterprises? 13. What organizations are established in Russia to participate in work with ISO? Name their main functions. 14. What is the product information coding? 15. What is the level of standardization and unification? 16. Give the definition of comprehensive standardization. 17. Describe the content of the Unified system of technological preparation of production. 18. What is the essence of advanced standardization? 19. What is a state standard? 20. Explain the structure and procedure for developing an industry standard. 21. What is an enterprise standard? 22. Explain the essence of the state supervision over implementation and execution of standards.

109

Section 3

BASICS OF CERTIFICATION

Chapter 1

BASIC CONCEPTS OF CERTIFICATION

1.1. History of certification development in the Republic of Kazakhstan The term “certification” appeared in everyday life relatively recently, but certification as a procedure has been used for a long time and the term “certificate” has been known since the 19th century. The Encyclopedic Dictionary of F.A. Brockhaus and I.A. Efron, published in 1890-1907, provides several definitions of a certificate, one of which is: “certificate, Fr. Identification”. There is information that manufacturers of goods have long guaranteed the quality of their products, including in writing, i.e. supplied them with “statements of conformity”. In metrology, certification has been known for more than 100 years as an activity in official calibration and stamping (or sealing) of measuring instruments. For several centuries, the so-called “classification organizations” have been operating, which being nongovernmental and independent organizations evaluate the safety of vessels for their insurance purposes. Essen112

Chapter 1. Basic concepts of certification

tially, this is also a certification. An example of a classification organization is the Lloyd’s Register – the most authoritative international organization having offices in 127 countries of the world and remaining the world leader of certification organizations for two centuries. Certification of devices, equipment and household appliances for electromagnetic compatibility started in Germany in 1934, in the USA – in 1953, and since 1991 this type of certification has become a mandatory procedure in many countries of the world. The predecessor of the domestic certification was the certification of exported products in the USSR. In the former USSR, the process of forming a certification system can be divided into two periods: the first – before the introduction of the certification system and the second – after its introduction in 1984. Before the introduction of the certification system, there was a system of state testing of measuring instruments, aviation, agricultural, automotive and other types of equipment in the country. In 1979, the most important types of products for industrial purposes and household goods were subjected to tests. This system was brought into full compliance with the regulations of the international certification standards existing at that time, which included not only the initial test procedures, but also subsequent inspection tests to monitor the stability of quality. However, lated the state testing of almost all types of products except for the defense equipment and measuring instruments was canceled. The second stage in the certification system formation is related to the adoption of the Resolution of the Council of Ministers of the USSR in 1984, which introduced mandatory certification of engineering products and the approval of the governing regulatory document RD 50-596-86 “Temporary regulation on certification of engineering products in the USSR”. Implementation of a set of actions was provided, as a result of which, the compliance of domestic engineering products with the requirements of international or national standards of countries-importers of these products or other documents established by international certification systems or certification agreements would be confirmed by means of a special document – certificate or conformity mark.

113

114

Section 3. Basics of certification

Thus, the system of engineering products certification, which solved many organizational and methodological issues can be considered as a prototype of the future system of certification of products and services in the CIS countries, including Kazakhstan. At the same time, the compliance of products with the established requirements was evaluated in the USSR in other forms, such as: – certification by quality categories; – state acceptance of products; – state tests; – state supervision of standards. After the collapse of the USSR, product certification in Kazakhstan in terms of quality, state tests and state acceptance of products was officially canceled. A progressive step in the establishment of certification in the Republic of Kazakhstan relates to the adoption of the Law «On Protection of Consumer Rights» in 1991, which considers the mandatory testing of products (services) according to characteristics ensuring the safety of people’s life, health and property and environmental protection. Verification and control of these indicators are possible only through certification. The consumer rights for the proper quality and safety of products (services), for complete and reliable information both about the product (service) and about the persons involved in its manufacture and sale are legislated. The Committee on Standardization, Metrology Certification of the Republic of Kazakhstan was established in 1992. The basis for establishment and development of the State Certification System was the Law of the Republic of Kazakhstan “On Standardization and Certification”, adopted on January 18, 1993. Kazakhstan was one of the first among the states of the Commonwealth to adopt such a law. However, two Laws of the Republic of Kazakhstan “On Certification” and “On Standardization” approved in 1999, lost their legal force in 2004. As Kazakhstan was and is striving to become a member of the World Trade Organization since 1993, it was necessary to change the

Chapter 1. Basic concepts of certification

approaches to standardization work, change its priorities, especially in terms when product safety requirements in accordance with the international practice are regulated by voluntary technical regulations and standards. It was necessary to change the emphasis in terms of product quality and safety. The state had to assume only that part of control, which is its priority in terms of the national security (safety of life, the environment, property), while liability for the quality and safety of the products should have been placed directly on the manufacturer. To implement the above tasks, the Law of the Republic of Kazakhstan “On Technical Regulation” was adopted on November 9, 2004. This Law regulates social relations by definition, establishment, application and execution of mandatory and voluntary requirements for products, services, product life cycle processes, conformity assessment, accreditation and state control in technical regulation. The emergence of this law was accompanied by the new terms: technical regulations, conformity assessment, etc. The state system of technical regulation replaced the standardization and certification systems. In accordance with the Law of the Republic of Kazakhstan “On Technical Regulation”, the state system of technical regulation is a combination of state bodies, individuals and legal entities carrying out work in technical regulation within their competence, as well as regulatory legal acts, standards and normative technical documents. In turn, technical regulation is the legal and normative regulation of relations linked with the determination, establishment, application and execution of mandatory and voluntary requirements for products, services, processes, including compliance, accreditation and state control over compliance with established requirements, exclusion of sanitary and phytosanitary measures. The objects of technical regulation are products, services, processes. Subjects of technical regulation are state bodies, as well as individuals and legal entities operating on the territory of the Republic of Kazakhstan and possessing the right to use objects of technical regulation in accordance with the civil legislation of the Republic of Kazakhstan.

115

116

Section 3. Basics of certification

1.2. Essence of certification Certification is a guarantee to the consumer that the products meet the standard or certain quality requirements. Certification is based on standards and on testing according to certification standards. Certification is carried out to create conditions for the activities of enterprises, institutions, organizations and entrepreneurs in the unified commodity market of the Russian Federation, as well as to participate in international economic scientific and technical cooperation and international trade; to assist consumers in the competent choice of products; to provide consumer protection from the manufacturer’s unfairness (seller, performer); to monitor safety of products for the environment, life, health and property; to confirm product quality indicators declared by the manufacturer. Certification is a method of objective control of product quality, its compliance with established requirements. It is divided into mandatory and voluntary, self-certification and certification by a third party. Mandatory certification is a means of state control over product safety. Voluntary certification contributes to the competitiveness of products. Self-certification performs all the necessary actions and declares this with a special document or by putting a certification mark on the product, or with an accompanying document. In this case, the consumer receives information about the test methods used in the enterprise. Third party certification is carried out by a system of bodies that are formally not related either to the manufacturer or to the consumer of products. This system of bodies includes official testing centers (laboratories), inspection bodies and national standards organizations. Any certification system is based on standards (state, enterprise, technical conditions). Confirmation that the products meet the requirements of the standards is carried out by means of a special document – certificate. ISO has a certification committee called CERTICO. This committee has prepared a set of principles for certification called the Code of ISO/IEC Principles on Third-Party Certification Systems for Compliance with Standards. The Code is based on the need to apply inter-

Chapter 1. Basic concepts of certification

national standards in national certification systems. The activities of the national certification body is regulated by the legislation of the Republic of Kazakhstan on certification. 1.3. Certification system The certification system is created by government authorities, enterprises, institutions, organizations and is a set of certification participants performing certification according to the rules established in this system in accordance with the Certification Law. The certification system may include enterprises, institutions and organizations regardless of their form of ownership, as well as public associations. It may also include several homogeneous product certification systems. It is subject to state registration in the manner established by the State Standard of Russia. The concept and composition of a certification system is important not only in theoretical but also in practical terms. The system can be created only by legal entities. The law provides for two components of the certification system: certification participants and certification rules. The certification participants include: state bodies, organizations that are the creators of the certification system, testing laboratories (centers), central certification system bodies, product manufacturers. Certification rules mean the regulatory documents governing all aspects of the system. A document issued according to the certification system rules to confirm the compliance of certification products with the established requirements is called the certificate of conformity. The content of the certificate is determined in the system depending on the chosen certification scheme and the category of applicant. The certification system is created for a certain type of homogeneous products, including large groups of products with a single functional purpose, principles of operation, methods of control and testing. A specific list of goods is determined by the documents of the system or the general lists of products by reference to the codes of product classifiers (OKP) or the commodity nomenclature of foreign

117

118

Section 3. Basics of certification

economic activity, as well as by indicating the relevant state standards and documents equivalent to them. Separate certification systems for homogeneous products can be combined into a single, larger system, all links of which are guided by common principles and documents, which does not exclude the possibility of taking into account the specifics of individual systems in their governing documents. The system of mandatory certification of the State Standard of Russia is this unifying system. The organizational structure of the state certification system consists of: – National Certification Body of Russia; – Certification bodies for specific products; – accredited testing laboratories (centers); – manufacturers and suppliers of products. State Standard of Russia performs the following functions: – development and improvement of basic organizational and methodological documents of the system; – establishment of reference and technical documentation (RTD), establishing the order for certification of specific types of products; – information on the certification results. Certification is carried out for compliance with the state standards; international and foreign standards; other RTD at the choice of the applicant. Exported products are certified for compliance with the requirements of national regulatory and technical documentation for importing countries. During certification of products within the international certification systems, of which Russia is a participant, its compliance with the requirements of international technical and technical documentation adopted in these systems is confirmed. Texts of standards and other regulatory and technical documents used for product certification are stated exactly in accordance with the requirements of ISO/IEC 7 Guidelines “Requirements for standards used for product certification”. Since certification is based on standards, there is a close relationship between the certification and standardization bodies, regardless of whether they are part of the same organization or not.

Chapter 1. Basic concepts of certification

1.4. Certification procedure Procedure for obtaining certificate of conformity by the manufacturer. The manufacturer (supplier) of products (applicant) for obtaining a certificate of conformity sends an application to the certification body for its implementation. The authority informs the applicant of its decision to conduct tests in an accredited testing laboratory (center) of product samples, to verify production and sets deadlines. In case of positive results of product testing, availability of a production certificate or a certificate for a quality system, an accredited testing laboratory issues a certificate and, upon receipt of a registration number in the State Standard of Russia, issues it to the manufacturing enterprise. In case of making changes in the design of the product or the technology of its production, which may affect the quality of the products, a decision is made whether new tests are necessary or check the state of production of these products. Recognition of foreign certificates of conformity. The decision on recognition and registration of certificates issued by certification bodies of other countries for domestic and imported products used in the country is implemented by the State Standard of Russia or another authorized certification body. Certificates or similar documents (licenses, approvals) issued in international systems to which Russia and the applicant’s country have joined or agreements between certification bodies in Russia and this country on mutual recognition of certificates are recognized. The order for such recognition is established by the rules of these systems or agreements. During the recognition period, the State Standard of Russia or another certification body may conduct the repeated tests (in full or according to certain characteristics) to confirm the compliance of products with the established requirements. At the request of the certification body, the applicant sends a sample of certified products. Verification of the manufacturing state of certified products. Verification of the manufacturing state of the certified products can

119

120

Section 3. Basics of certification

be done in two ways: by certifying it or by certifying a quality system developed based on ISO 9000 standards. Attestation of manufacturing of the certified products is a set of measures and sufficient conditions to ensure the stable level of requirements, characteristics, indicators that are controlled during certification. At that, the effectiveness of control over all production conditions and product characteristics, its component parts, and materials used, on which the specified level of requirements depends, is assessed. During attestation of the inter-industry production the following is checked: – the adequacy and quality of control operations in the manufacture of products, including metrological support; – the state of technological operations determining the level of performance and product requirements that are controlled during certification; – stability of compliance of manufactured products with the requirements of RTD; – distribution of staff liability for ensuring the product quality. If serious shortcomings are found in ensuring the stable quality of the products offered for certification, a deadline for re-certification is established subject to the complete elimination of the noted shortcomings. If the test results are positive, the State Standard of Russia issues a certificate of production to the manufacturer. Certification of the product quality system is the activity of organizations accredited by the State Standard of Russia to verify, evaluate and certify the conformity of the quality system of the inspected enterprise with the requirements of the state or international standard for the quality system. The certification of the quality system is carried out in accordance with the set of governing documents “Certification of product quality systems” approved by the State Standard of Russia. Product Testing. Tests for certification are carried out on samples, design, composition and manufacturing technology, which should be

Chapter 1. Basic concepts of certification

the same as that of the samples supplied to the consumer (customer). The number of samples, the order for selection, identification and storage shall be established by organizational and methodological documents on certification of a specific type of product and test method. Testing of imported products is carried out in Russia. Supervision of certification and quality of the certified products. Supervision of certification, stability of the quality of certified products and the state of their production is carried out by the territorial bodies of the State Standard of Russia. The scope, content, and the order for supervision are established in the organizational and methodological documents on certification of specific types of products. They provide for the frequency and scope of inspection tests of certified products in the accredited testing laboratories (centers). According to the results of supervision, the State Standard of Russia may suspend or cancel the validity of the certificate of conformity and the right to use the conformance mark, certificate of production. The decision to suspend the said documents is taken when the conformity of products or the state of production to the established requirements cannot be restored as a result of immediate measures. Certification information. The State Standard of Russia conducts accounting and creates a fund of: – certificates issued and valid in Russia; – organizational and methodological documents for the certification of specific types of products; – certificates of production of certified products; – certificates of accreditation of testing laboratories (centers). The State Standard of Russia periodically publishes information on product certification work, including: – list of products for which certificates are issued; – list of accredited testing laboratories (centers); – list of certified productions of certified products. In case of disagreement with the certification results, the parties concerned may file an appeal with the State Standard of Russia on

121

122

Section 3. Basics of certification

the possibility of mutual recognition and comparison of test results, which requires the harmonization of rules, principles and objectives of certification. For this, the Rules of certification in the Republic of Kazakhstan and other documents were adopted. Based on the acting laws in certification, organizational and methodological principles have been developed that determine the practice of certification in Russia. Test questions to the module: 1. Give the definition of certification. 2. What is a conformity mark? 3. What is the main purpose of the global certification concept? 4. When was the mandatory certification system introduced in Russia? 5. Explain the structure of the legislative and regulatory basis for certification. 6. Explain the tasks of the State Standard of the Republic of Kazakhstan in certification. 7. Define the certificate of conformity. 8. Explain the reasons for division of certification into mandatory and voluntary ones. 9. List the main participants of the certification procedure. 10. What are the responsibilities of certification bodies and testing laboratories? 11. What can be the subject of certification? 12. In what cases is a product labeled with a CE mark? 13. List the steps of the certification process. 14. What are the tasks of the inspection control during certification? 15. In what cases does the suspension or cancellation of a certificate of conformity take place? 16. What are the main functions of the certification body? 17. What are the functions of the coordination board of the certification body? 18. List the documents required when applying for accreditation of the certification body. 19. What are the main functions of the certification body? 20. What criteria should test laboratories meet for certification? 21. List the main stages of certification tests.

Chapter 2

TECHNICAL REGULATION

The rationing system in standardization and certification of products, production processes and services in Kazakhstan has recently been subjected to fundamental, not to say, revolutionary transformations. There are several reasons for the adoption of this law. First of all, further red tape reduction of the economy, refusal of excessive rationing and petty administrative care by the federal executive bodies, a serious increase in the level of legal regulation of activities related to the circulation of products, performance of works and the provision of services. Another reason for the emergence of the Law is the upcoming entry of Russia into the World Trade Organization (WTO) and the need to fulfill the requirements of this and other international economic organizations. Thus, the Agreement on Technical Barriers to Trade describes the main barriers for checking compliance as the discrepancies between laws of different countries, differences in standards and procedures. It is established that standards should be of a recommendatory nature, that national standards should mostly correspond to interna123

124

Section 3. Basics of certification

tional ones, and mandatory requirements should be contained in technical regulations. The technical regulation refers to the legal regulation of relations in: 1. development, adoption, application and execution of mandatory requirements for products, production processes, operation, storage, transportation, sale and disposal (hereinafter referred to as – to products and processes); 2. establishment and application of requirements for products, production processes, operation, storage, transportation, sale and disposal, performance of works or provision of services on a voluntary basis; 3. in evaluation of compliance. In accordance with the Law, the following main activities on technical regulation can be distinguished: – technical regulations; – standardization; – confirmation of compliance. The law does not apply to the scope of activities related to the functioning of the unified communications network of the Republic of Kazakhstan, to state educational standards, accounting regulations, securities issue standards and auditing rules. The objects of mandatory requirements are: – products; – production processes (requirements for its production); – rules for the use of products (consumption, use); – rules for storage, transportation, sale and disposal of products. It should be noted that based on the Law, the products mean the result of activity provided in tangible form and intended for further use for economic and other purposes. These are products for production purposes (equipment, machines, devices, etc.), consumer goods (including energy products, water, etc.), buildings and structures for both public and state, and individual use. Objects of voluntary requirements are the same, but added the works and services. That is, if both voluntary and mandatory require-

Chapter 2. Technical regulation

ments are applied to products and the related processes, only voluntary requirements are accepted for the execution of works and the provision of services. The Law does not provide the concept of “work” and “service.” The state standard GOST R 50646-94 defines “work” as a material service, its end result is expressed in a material form. Work may include housing and communal services, domestic work on the repair and manufacturing of products, catering services, transport, etc. The works and services themselves in the meaning of this Law are the social and cultural services, the result of which has no material form and not related to products. No mandatory requirements are set for such services. The main principles of technical regulation include: – application of uniform rules for establishing the requirements for products and processes, performing work or providing services – to ensure compatibility of requirements and forms of their presentation in technical regulations and standardization documents; – compliance of technical regulation with the levels of development of the national economy, material and technical base and science and technology – to ensure the practical application of the requirements of the Law; – independence of accreditation and certification bodies from manufacturers, sellers, performers and purchasers – lack of organizational, administrative, economic, financial and any other form of dependence; – unified system and rules of accreditation; – unity of the rules and methods of research and measurements with mandatory conformity assessment – to exclude the possible negative consequences of unreliable measurement results in case of violation of the measurement unity; – unity of application of the technical regulations requirements regardless of the types or features of transactions; – inadmissibility of competition restrictions in implementation of accreditation and certification – emphasizing the commercial nature of the activities of certification bodies and testing laboratories

125

126

Section 3. Basics of certification

and the inadmissibility of monopolization of activities by any of these bodies; – inadmissibility of combining the powers of the state control body and the certification body – emphasizing the fundamentally different nature of state control bodies and certification bodies whose functions can be performed by persons and organizations carrying out the entrepreneurial activity; – inadmissibility of combining the authority for accreditation and certification by one authority – emphasizing the state function of accreditation; – inadmissibility of extra-budgetary financing of state control over compliance with the requirements of technical regulations – ensuring the financial independence of state control bodies for the effectiveness of their activities. Exception is the technical regulation in defense products (works and services) and products (works and services), information about which is a state secret. In this area, mandatory requirements for work and services in the absence of technical regulations may be established by the federal executive authorities. It should be noted that due to the revolutionary nature of the Law, many regulatory legal acts of the Republic of Kazakhstan in terms of the scope of the Law contradict its provisions in one way or another. This applies to certain provisions of the Civil Code, the Criminal Code, the Administrative Code, the laws “On Protection of Consumer Rights”, “On sanitary and epidemiological welfare of the population”, etc. Therefore, it is necessary to compare their provisions with the corresponding provisions of the Law when applying these legal acts. Since all acts adopted by the federal executive bodies on issues regulated by the Law are only of an advisory nature, all previously issued regulatory legal acts lose their mandatory character from the day the Law enters into force. The only exceptions are the mandatory requirements for products and related processes established by the federal executive bodies, which are valid until the technical regulations come into force only for purposes consistent with the objectives of the technical regulations.

REFERENCES

1. Law of the Republic of Kazakhstan No. 603 dated November 9, 2004 “On Technical Regulation” 2. Law of the Republic of Kazakhstan dated June 7, 2000 “On ensuring the uniformity of measurements” 3. Basics of standardization, metrology, certification and quality management – Almaty: Kazakhstan Marketing Association, 2003. – 564 p. 4. Berdibayev M.S. Physical metrology: study guide. – Almaty: Kazakh University, 2003. – 78 p. 5. Mutanov G., Umyrzag R. Fundamentals of standardization, metrology, certification. Quality management. Textbook for students and professionals. – Astana, 2003. – 169 p. 6. Askarov A.S. Standardization, metrology and certification. Tutorial. – Almaty: Economy, 2011. – 321 p. 7. Lifits I.M. Standardization, metrology and conformity assessment. Textbook for universities. – Yuright, 2010. – 315 p. 8. Krylov G.D. Fundamentals of standardization, metrology, certification. Textbook. – M.: Unity-Dana, 2012. – 711 p. 9. Sergeyev A.G. M. Certification. Tutorial. – Logos, 2008. – 176 p. 10. Sergeyev A.G., Latyshev M.V., Teregerya V.V. Metrology, standardization, certification: Tutorial. – M .: Logos, 2003 – 536 p. 11. Certification: Textbook – Moscow: FORUM: INFRA – M, 2003. – 256 p. 12. Basakov M.I. Certification of products and services with the basics of standardization and metrology: (Textbook. Manual) / Mikhail Ivanovich Basakov. – 2nd edition revised and added. – Rostov-on-Don: Mart, 2002. – 254 p. 13. Goncharov A.A. Metrology, standardization and certification: studies. manual for universities / Anatoly Artemyevich Goncharov; A.A. Goncharov, V.D. Kopylov. – 2nd ed. – M.: Akademiya, 2005. – 239 p.

127

128

Section 3. Basics of certification 14. Krylova G.D. Fundamentals of standardization, certification, metrology: studies. for university students / Galina Dmitriyevna Krylova; G.D. Krylova. – 3rd ed., Revised and added. – M.: UNITY-DANA, 2006. – 671 p. 15. Lifits I.M. Standardization, Metrology and Certification: studies / Joseph Moiseyevich Lifits – 8th ed., Revised and added. – M.: Yuright, 2008. – 412 p. 16. Lavrischev O.A. Metrological assurance of thermophysical measurements: Metrological workshop for university students / Almaty: Kazakh University, 2004. – 138 p. 17. Khamkhanova D.N. Applied metrology: study guide. – Ulan-Ude, publishing house of the East-Siberia State Technology and Management University, 2006. – 160 p. 18. Ushakov I.E., Shishkin I.F. Applied metrology: a textbook for universities. – St-Petersburg, 2002. – 116 p. 19. Shakkaliyev A.A., Kanayev A.T., Alchikanova A.T. Standardization: textbook. – Astana: Kazakhstan Institute of Standardization and Certification, 2013. – 238 p.

Еducational issue

Askarova Aliya Sandybaevna Bolegenova Saltanat Alikhanovna Bolegenova Symbat Alikhanovna Lavrischev Oleg Aleksandrovich Manatbaev Rustem Kusayingazievich Maximov Valerу Yurevich Maksutkhanova Ardak Maksutkhanovna Shortanbayeva Zhanar Kaiyrzhanovna METROLOGY, STANDARDIZATION AND CERTIFICATION IN ENERGY SECTOR Manual for graduate students Editor L.E. Strautman Typesetting and cover design G. Kaliyeva Cover design photos were used from sites www.background-2672597_960_720.com

IB No. 12686

Signed for publishing 27.03.2019. Format 60x84 1/16. Offset paper. Digital printing. Volume 8,06 printer’s sheet. 80 copies. Order No. 1645. Publishing house Qazaq University Al-Farabi Kazakh National University KazNU, 71 Al-Farabi, 050040, Almaty Printed in the printing office of the Qazaq University Publishing House.

«ҚАЗАҚ УНИВЕРСИТЕТІ» баспа үйінің жаңа кітаптары Ландау Л.Д. Баршаға арналған физика. Физикалық дене: оқу құралы / Л.Д. Ландау, А.И. Китайгородский; орыс тілінен ауд.: А.К. Саймбетов, Б.Қ. Мухаметқали, Б.С. Кусманова [және т.б.]. – Aлмaты: Қaзaқ университеті, 2018. – 198 б. ISBN 978-601-04-3223-9 Бұл кітаптың негізгі мақсаты – оқырмандар үшін заманауи физиканың жетістіктері және негізгі идеяларын нақты түрде түсіндіру. Бақылаушыға байланысты физикалық дене екі жағдайда қарастырылады: инерциалды және инерциалды емес координаттық жүйелерде. Оқу құралының оқырмандар үшін физика ғылымына кірісуде маңызы зор. Сaймбетов A.К. Өлшеуіш техникaның негіздері: оқу құрaлы / A.К. Сaймбетов, М.М. Ғылымжaновa, Н.Б. Құттыбaй. – Aлмaты: Қaзaқ университеті, 2018. – 216 б. ISBN 978-601-04-3224-6 Оқу құрaлы электронды техникaның жұмыс істеу принципін, өлшеу қaтеліктері мен негізгі қaғидaлaрын қамтиды. Бөлімдер өлшеу жүргізу жүйелерінің құрылымдық бөлігінің қызмет aтқaру ерекшеліктерінен және олaрдың тұрғызылуының бaсты қaғидaлaрынaн тұрaды. 5В071900 – «Рaдиотехникa, электроникa және телекоммуникaциялaр» мaмaндығының студенттері үшін aрнaлып жaзылғaн. Саймбетов А.К. Талшықты-оптикалық байланыс желісі: оқу құралы / А.К. Саймбетов, А.А. Толегенова, Н.Б. Құттыбай. – Алматы: Қазақ университеті, 2018. – 194 б. ISBN 978-601-04-3136-2 Қазіргі уақытта байланыс қызметін ұсынушылар әр жыл сайын талшықтыоптикалық кабельдің мыңдаған километрін жер астымен, теңіз, көлдердің түбімен, жерасты жолдары арқылы тартады. Талшықтыоптикалық технологиялар аймағында белсенді зерттеулер жүргізіліп отырады. Оптикалық кабель (ОК) жарық толқынының сәйкесінше белгіленген өлшеміндегі оптикалық диапазонында электромагниттік тербелістерді тасымалдай отырып, ақпараттарды жеткізеді. Оптикалық талшықтарда ұзындықтары 16,6 мкм-ді құрайтын инфрақызыл толқындар қолданылады. Келешекте толқындардың жұмыс аралығы инфрақызыл толқындар тәрізді 5-тен 10 мкм-ге дейін толқын ұзаруы мүмкін. Ұсынылып отырған оқу құралында талшықты оптика элементтері және құрылғыларының жұмыс істеу принциптері, негізгі сипаттамалары, ақпаратты жіберу жолдары қарастырылады. Оқу құралы 5В071900 – «Радиотехника, электроника және телекоммуникациялар» мамандығының студенттеріне арналады.

Кітаптарды сатып алу үшін «Қазақ университеті» баспа үйінің маркетинг және сату бөліміне хабарласу керек. Байланыс тел: 8(727) 377-34-11. E-mail: [email protected], cайт: www.read.kz, www.magkaznu.com