Electrical and Electronics Measurements and Instrumentation About the Authors Prithwiraj Purkait obtained his BEE, MEE and PhD degrees from Jadavpur University, Kolkata He worked with M/s Crompton Greaves Ltd, Mumbai, as a Design Engineer for one year He was involved in post-doctoral research in the University of Queensland, Australia, during 2002-2003, and as Visiting Academic Research Fellow during 2005 and 2007 Presently, he is Professor, Department of Electrical Engineering and Dean, School of Engineering, at Haldia Institute of Technology, Haldia, West Bengal His current areas of interest include PC/DSP based instruments, motion and industrial process control, insulation-condition assessment techniques and advanced signal-processing applications Dr Purkait has published extensively in international journals and conference proceedings on various topics related to his research paradigm Budhaditya Biswas obtained his BEE and MEE from University of Kalyani, Nadia and Bengal Engineering and Science University (BESU), Shibpur, in the years 2002 and 2006 respectively He started his career as a lecturer in Haldia Institute of Technology, Haldia, in 2006 At present, he is working as Assistant Professor at the Department of Electrical Engineering in RCC Institute of Information Technology, Kolkata He has been teaching for over 6 years and his areas of interest include power systems, especially the design of microcontroller-based numerical adaptive relay, digital instrumentation, and data acquisition He has to his credit publications in international and national conference proceedings on various topics related to his research domain Santanu Das obtained his BEE and MEE from Bengal Engineering and Science University, Howrah, West Bengal He has submitted his PhD thesis (in electrical engineering) to Jadavpur University, Kolkata, for evaluation Earlier, Prof Das worked at Asansol Engineering College, Asansol, as Lecturer Presently, he holds the post of Associate Professor and Head, Department of Electrical Engineering Haldia Institute of Technology, Haldia He has published more than 20 research papers in international journals and conference proceedings on topics related to his research domains His current fields of research interest include fault diagnosis and condition monitoring of electric motors, PLC and microcontroller-based motion control, power electronics and drives Chiranjib Koley obtained his B.Tech from HIT, Haldia, M.Tech from IIT Delhi and PhD from Jadavpur University, Kolkata He received the EFIP Scholarship in 2001 from the Government of India Presently, he is Associate Professor in Department of Electrical Engineering, National Institute of Technology, Durgapur, West Bengal His current areas of interest include signal processing, machine learning, and measurement and instrumentation He has published extensively in national and international journals, and conference proceedings on various topics related to his research areas Electrical and Electronics Measurements and Instrumentation Prithwiraj Purkait Professor Department of Electrical Engineering and Dean, School of Engineering Haldia Institute of Technology Haldia, West Bengal Budhaditya Biswas Assistant Professor Department of Electrical Engineering RCC Institute of Information Technology Kolkata, West Bengal Santanu Das Associate Professor Department of Electrical Engineering Haldia Institute of Technology Haldia, West Bengal Chiranjib Koley Associate Professor Electrical Engineering Department National Institute of Technology (NIT) Durgapur Durgapur, West Bengal McGraw Hill Education (India) Private Limited Published by McGraw Hill Education (India) Private Limited P-24, Green Park Extension, New Delhi 110 016 Electrical and Electronics Measurements and Instrumentation Copyright © 2013, by McGraw Hill Education (India) Private Limited No part of this publication may be reproduced or distributed in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise or stored in a database or retrieval system without the prior written permission of the publishers The program listing (if any) may be entered, stored and executed in a computer system, but they may not be reproduced for publication This edition can be exported from India only by the publishers, McGraw Hill Education (India) Private Limited ISBN (13): 978-1-25-902959-2 ISBN (10): 1-25-902959-X Vice President and Managing Director: Ajay Shukla Head—Higher Education Publishing and Marketing: Vibha Mahajan Publishing Manager—SEM & Tech Ed: Shalini Jha Editorial Executive: Koyel Ghosh Manager—Production Systems: Satinder S Baveja Assistant Manager—Editorial Services: Sohini Mukherjee Senior Production Manager: P L Pandita Assistant General Manager (Marketing)—Higher Education: Vijay Sarathi Senior Product Specialist: Tina Jajoriya Senior Graphic Designer—Cover: Meenu Raghav General Manager—Production: Rajender P Ghansela Manager—Production: Reji Kumar Information contained in this work has been obtained by McGraw Hill Education (India), from sources believed to be reliable However, neither McGraw Hill Education (India) nor its authors guarantee the accuracy or completeness of any information published herein, and neither McGraw Hill Education (India) nor its authors shall be responsible for any errors, omissions, or damages arising out of use of this information This work is published with the understanding that McGraw Hill Education (India) and its authors are supplying information but are not attempting to render engineering or other professional services If such services are required, the assistance of an appropriate professional should be sought Typeset at Text-o-Graphics, B-1/56, Aravali Apartment, Sector-34, Noida 201 301, and printed at Cover Printer: Contents Preface Guided Tour Concept of Measurement Systems 1.1 Introduction 1.2 Fundamental and Derived Units 1.3 Standards and their Classifications 1.4 Methods of Measurement 1.5 Measurement System and its Elements 1.6 Classification of Instruments 1.7 Definitions of Some Static Characteristics 1.8 Measurement of Errors 1.9 Loading Effects Exercise Analog Meters 2.1 Introduction 2.2 Classification of Analog Instruments 2.3 Principle of Operation 2.4 Operating Torques 2.5 Constructional Details 2.6 Permanent Magnet Moving Coil Instrument 2.7 Extension of Range of PMMC Instruments 2.8 Moving-Iron Instruments 2.9 Electrodynamometer-Type Instruments 2.10 Electrostatic Instruments 2.11 Induction-type Instruments 2.12 Electrothermal Instruments 2.13 Rectifier-type Instruments 2.14 True rms Voltmeter 2.15 Comparison between Different Types of Instruments Exercise Instrument Transformers 3.1 Introduction 3.2 Advantages of Instrument Transformers 3.3 Current Transformers (CT) 3.4 Theory of Current Transformers 3.5 Errors Introduced by Current Transformers 3.6 Operational Characteristics of Current Transformers 3.7 Design and Constructional Features of Current Transformers 3.8 Precautions in Use of Current Transformer 3.9 Potential Transformers (PT) 3.10 Theory of Potential Transformers 3.11 Errors Introduced by Potential Transformers 3.12 Operational Characteristics of Potential Transformers 3.13 Design and Constructional Features of Potential Transformers 3.14 Differences between CT and PT Exercise Measurement of Resistance 4.1 Introduction 4.2 Measurement of Medium Resistances 4.3 Measurement of Low Resistances 4.4 Measurement of High Resistances 4.5 Localisation of Cable Faults Exercise Potentiometers 5.1 Introduction 5.2 A Basic dc Potentiometer 5.3 Crompton’s dc Potentiometers 5.4 Applications of dc Potentiometers 5.5 AC Potentiometers 5.6 Classification of AC Potentiometers 5.7 Advantages and Disadvantages of AC Potentiometers 5.8 Applications of AC Potentiometer Exercise AC Bridges 6.1 Introduction 6.2 Sources and Detectors in AC Bridges 6.3 General Balance Equation for Four-Arm Bridge 6.4 Measurement of Self-Inductance 6.5 Measurement of Capacitance 6.6 Measurement of Frequency 6.7 Wagner Earthing Device Exercise Power Measurement 7.1 Introduction 7.2 Power Measurement in dc Circuits 7.3 Power Measurement in ac Circuits 7.4 Electrodynamometer Type Wattmeter 7.5 Induction-type Wattmeter 7.6 Power Measurement in Polyphase Systems 7.7 Power Measurement in Three-Phase Systems 7.8 Reactive Power Measurements 7.9 Power Measurement with Instrument Transformers Exercise Measurement of Energy 8.1 Introduction 8.2 Single-Phase Induction-type Energy Meter 8.3 Errors in Induction-type Energy Meters and Their Compensation 8.4 Testing of Energy Meters Exercise Cathode Ray Oscilloscope 9.1 Introduction 9.2 Block Diagram of a Cathode Ray Tube (CRT) 9.3 Electrostatic Deflection 9.4 Time Base Generator 9.5 Vertical Input and Sweep Generator Signal Synchronisation 9.6 Measurement of Electrical Quantities with CRO 9.7 Measurement of Voltage and Current 9.8 Measurement of Frequency 9.9 Measurement of Phase Difference 9.10 Sampling Oscilloscope 9.11 Storage Oscilloscope 9.12 Multi-Input Oscilloscopes 9.13 Frequency Limitation of CRO Exercise 10 Electronic Instruments 10.1 Introduction 10.2 Merits and Demerits of Digital Instruments over Analog Ones 10.3 Performance Characteristics of Digital Meters 10.4 Digital Multimeter 10.5 Digital Frequency Meter 10.6 Digital Voltmeters (DVMs) 10.7 Signal Generators Exercise 11 Sensors and Transducers 11.1 Introduction 11.2 Electrical Transducers 11.3 Linear Variable differential Transformer (LVDT) 11.4 Strain Gauges 11.5 Electromagnetic Flow Meter 11.6 Temperature Transducers 11.7 Pressure Measurement Exercise 12 Magnetic Measurements 12.1 Introduction 12.2 Types of Magnetic Measurements Antenna size 17.2 Application Software 14.13 Aquadog 9.1 Arbitrary waveform generator 10.14 Astatic 7.18 Astatic electrodynamometer instruments 7.18 Avalanche Diode 18.6 Average deflecting torque 7.11 B Ballistic galvanometer 12.1 Band-Pass (selective) Filter 14.8 Band-stop (Notch) Filter 14.9 Barkhausen Criteria 13.3 Barretter 17.16 Bar-type CT 3.15 Baseband signal 17.15 Basic Requirements of a Transducer 11.2 Basic Transistor LC Oscillator Circuit 13.5 Bearings 2.5 BFSK 17.12 Binary Weighted DAC 14.20 Blondel’s Theorem 7.25 Bolometer 17.16 Brake magnet 8.5 Bridge and ac Potentiometer Methods 12.27 Burden 3.2 Burrows Permeameter 12.23 Bushing-type CT 3.16 Butterworth Filter 14.10 C Calibration of ammeter 5.6, 5.18 Calibration of Ammeter by Potentiometer 5.10 Calibration of the Ballistic Galvanometer 12.5 Calibration of voltmeter 5.5, 5.18 Calibration of Voltmeter by Potentiometer 5.9 Calibration of wattmeter 5.6, 5.19 Calibration of Wattmeter by Potentiometer 5.10 Capacitance standards 1.3 Capacitive Transducers 11.23 Cathode Ray Oscilloscope (CRO) 9.1 Cathode Ray Tube (CRT) 9.1, 15.18 Central Processing Unit (CPU) 16.4 Characteristic frequency 13.15 Circular Chart Recorder 15.6 Clamp on type CTs 3.16 Cold Cathode Display 15.19 Cold junction 11.15 Colpitts Crystal Oscillator 13.16 Colpitts Oscillators 13.9 Communication Systems 17.14 Comparison between different types of instruments 2.47 Comparison methods 1.8 Compensating coil 7.17 Compensation for pressure coil inductance 7.15 Compensation for voltage variation 8.14 Conductive mesh 9.19 Contacts and lead resistances 4.20 Controller 14.26 Controlling system 2.3 Controlling torque 2.2, 2.3, 7.11 Control Program 16.2 Coordinate Potentiometer 5.14 Counters 16.3 Counter/Timer and Pulse I/O 14.26 Counter/Timers Subsystems 14.4 Counting system 8.6 Creeping Error 8.12 Creep test 8.14 Critical angle 18.1 Critically damped 2.3 Crompton’s dc potentiometer 5.2 Cross-over Distortion 13.36 Crystal Oscillators 13.14 CT transformation 8.5 Current coil 1.3, 2.32, 2.33, 7.5 Current standards 4.19 Current terminals 3.2 Current transformer 7.35, 14.6 D D/A Conversion 14.19 DAC Performance 14.22 Damping force 2.3 Damping torque 2.2 DAQ 14.3 DAQ Hardware 14.3 Data acquisition 14.1 Data Logger 15.15 Dead zone 1.16 Deflecting plates 9.1 Deflecting system 2.3 Deflecting torque 2.2, 2.14 Deflection factor 9.5 Deflection methods 1.8 Deflection sensitivity 9.5 Deflection-type instrument 1.15 Delta-sigma modulation 14.20 Derived units 1.2 De Sauty’s bridge 6.17 Detection of Low Level Signals 10.2 Determination of Hysteresis Loop 12.17 Determination of Magnetising Curve 12.15 Dielectric losses 6.18 Differential transformers 11.22 Digital frequency meter 10.7 Digital input/output subsystems 14.4 Digital inputs 14.24 Digital instruments 1.13 Digital modulation 17.11 Digital multimeter 10.5 Digital pattern generator 10.14 Digital recorders 15.15 Digital sensors 14.5 Digital storage oscilloscope 9.19 Digital tape recording 15.17 Digital to Analog (D/A) converter 10.4 Digital Voltmeter (DVM) 10.9 Diode detector 17.17 Direct comparison methods 1.8 Direct deflection method for high resistance measurement 4.26 Display system 15.18 Dissipation factor 6.19 Dot Matrix Display 15.22 Driver Software 14.13 Drysdale polar potentiometer 5.14 DSO 9.19 Dual Beam Oscilloscopes 9.23 Dual-Slope Integrating-Type DVM 10.11 Dual trace oscilloscopes 9.21 Dynamic range 14.22 Dynamometer 7.5 Dynamometer-type wattmeter 7.5 E Eddy-current damping 2.8, 2.10 Eddy-current Errors 7.17 Eddy current losses 3.18 Eddy currents 2.3 Effect of power factor on wattmeter readings 7.29 Electrical instruments 1.14 Electrodynamic ammeter 2.32 Electrodynamic voltmeter 2.32 Electrodynamic wattmeter 2.33 Electromagnetic Flow meter 11.7 Electromagnetic spectrum 17.1 Electromagnetic wave spectra 17.3 Electron gun 9.1 Electronic instruments 1.14, 10.1 Electronic voltmeter (EVM) 10.2 Electrostatic instruments 2.37 Electrothermal instruments 2.41 Environmental errors 1.21 Error caused by vibration of the moving system 7.19 Error due to connection 7.16 Error due to overload 8.13 Error due to pressure coil capacitance 7.15 Error due to pressure-coil inductance 7.13 Error due to voltage variations 8.14 Errors in a Wheatstone bridge 4.16 Errors in Electrodynamometer-type Wattmeter 7.13 Errors occurring during the Measurement using thermocouple 11.16 Error Vector Magnitude (EVM) 17.13 Ewing Double Bar Permeameter 12.21 Extension of range of PMMC Instruments 2.18 Extension of range of rectifier instrument 2.45 External magnetic fields 7.18 F Fibre optic power measurement 18.7 Fictitious loading 7.9 Field coils 2.28 Filtering 14.5 Fixed coils 2.29 Flash/Parallel 14.15 Flat panel display 15.26 Flow meters 2.3 Fluid friction 2.8 Fluid-friction damping 2.9, 11.19 Fluxmeter 12.8 FM recording 15.13 Force summing devices 4.19 Four terminals 9.7 Free running 9.7 Free running sweep 10.6 Frequency counter 10.7 Frequency distortion 13.35 Frequency generator 9.24 Frequency Modulation (FM) 17.10 Frequency range of oscilloscope 2.17 Frequency Selective Wave Analyser 13.33 Frequency Shift Keying (FSK) 17.12 Full-scale deflection 2.18 Function Block Diagrams (FBD) 16.12, 16.16 Function generator 1.2, 13.26 G Gall Coordinate Potentiometer 5.15 Galvanometer 4.17 General Purpose Interface Bus (GPIB) 14.26 Graphic Recorders 15.2 Gravity Control 2.7 Gross error 1.19 Guarantee errors 1.17 Guard arrangement 4.25 Guard circuits 4.25 H Hair-spring 2.6 Hand-held programming 16.8 Hard beam 9.5 Harmonic distortion 17.5 Harmonic distortion analysers 13.35 Hartley Oscillator 13.6 Hay’s bridge 6.9 Heterodyne Sweep Generator 13.31 Heterodyne Wave Analyser 13.33 High Output Signal Quality 11.2 High-Pass Filter 14.7 High Q inductors 6.9 High Reliability and Stability 11.2 High Resistances 4.1 Hopkinson Permeameter 12.19 Hot-wire Instrument 2.41 Hybrid DAC 14.21 Hybrid Recorders 15.9 Hysteresis 3.18, 11.2 I IEEE 488 Interface 14.26 Illiovici Permeameter 12.22 Image Table Addresses 16.9 Indicating instruments 1.13 Indirect comparison methods 1.8 Indirect measurement methods 1.8 Induction-type instruments 2.39 Induction-type wattmeter 7.22 Inductive transducer 11.3, 11.20 In-phase’ potentiometer 5.15 Input/Output (I/O) Modules 16.6 Input Relays 16.3 Input resistance 10.2 Insertion errors 7.2 Instantaneous power 7.6 Instantaneous torque 7.11 Instrumental errors 1.21 Insulation resistance 4.30 Integrating instruments 1.13 Integrating-Type DVM (Voltage to Frequency Conversion) 10.13 Inter-modulation Distortion 13.36 Internally reflected 18.1 Internal Triggering (INT) 9.8 Internal Utility Relays 16.3 International ampere 1.4 International standards 1.2 Inter-turn capacitance 7.15 I/O Addresses 16.9 Ionisation transducers 11.26 J Jewel bearings 7.9 Jewels 2.5 K Kelvin’s Double-Bridge Method for Measuring Low Resistance 4.20 Kilowatt-hour (kWh) 8.1 L Ladder diagrams 16.12 LASER 18.4 LCD 15.23 LC oscillator 10.16 LC Oscillatory Circuit 13.3 Leakage flux 12.25 LED 15.19 Light Emitting Diode (LED) 15.19, 18.3 Limiting error 1.17 Linear Error 10.4 Linearisation 14.11 Linearity 11.2 Linear Variable differential Transformer (LVDT) 11.3 Liquid Crystal Display (LCD) 15.23 Lissajous patterns 9.12 Listener 14.26 Loading effect 1.22, 10.2 Localisation of cable faults 4.33 Loop tests 4.33 Loss angles 6.20 Loss of charge method for high resistance measurement 4.29 Low-pass filter 14.6 Low resistances 4.1 Luminosity 9.5 M Magnetic disk and tape type recorder 15.11 Magnetic flow meters 11.7 Magnetic measurements 12.1 Magnetic meter (Magmeter) 11.8 Magnetic shielding 12.30 Magnetic shunt 8.14 Magnetic tape 15.11 Magnetic testing 12.26 Manual instruments 1.15 Mark frequency 17.12 Maximum sampling frequency 14.22 Maxwell’s bridge method 12.28 Maxwell’s inductance bridge 6.4 Maxwell’s inductance-capacitance bridge 6.6 Measurement of current by potentiometer 5.6 Measurement of energy 8.1 Measurement of flux density 12.11 Measurement of frequency 9.12 Measurement of high voltage by potentiometer 5.6 Measurement of loss 18.8 Measurement of low resistances 4.19 Measurement of magnetic flux by Ballistic galvanometer 12.4 Measurement of magnetic leakage 12.25 Measurement of magnetising force (H) 12.13 Measurement of power by potentiometer 5.8 Measurement of resistance by potentiometer 5.7 Measuring RF voltages with a voltmeter 17.17 Mechanical instruments 1.14 Medium resistances 4.1 Meggar 4.30 Megohmmeter 4.30 Merits and demerits of digital instruments over analog 10.2 Meter constant 8.1 Microprocessor clocks 13.17 Microwave 17.3 Modified De Sauty’s bridge 6.18 Modulated signal 17.9 Modulating signal 17.9 Modulation 17.9 Modulation Error Ratio (MER) 17.13 Modulation oscillator 10.16 Mono shot 13.19 Monostable multivibrator circuits 10.3 Monotonicity 10.4 Moving coil 2.28, 2.29 Moving Iron or MI 4.6 Multimode fibres 18.2 Multi-range series ohmmeter 7.12 Murray Loop Test 4.34 N Network analyser 17.7 Network scattering parametres 17.9 Nixie tube 15.27 Noise floor 17.5 Noise shaping 14.20 Nominal ratio 3.7 Non-inductive resistance 7.9 Non-sinusoidal Oscillators 13.2 Null-type instruments 1.15 Nyquist Criterion 14.13 O Occupied bandwidth 17.4 Ohmmeter 4.2 One-shot 13.22 OP-AMP astable multivibrator 13.19 Optical detectors 18.5 Optical fibre 18.1 Optical power 18.7 Optical sources 18.2 Optical Time Domain Reflectometre (OTDR) 18.9 Oscillation transducers 11.27 Oscillator 13.1 Oscillographic recorders 15.15 Over-compensation for friction 8.12 Overdamped 2.3 Oversampling DACs or Interpolating DACs 14.20 Owen’s bridge 6.13 P Paperless recorders 15.9 PC-based data acquisition system 14.3 PDM recording 15.14 PDP 15.26 Percentage of distortion 17.5 Percentage ratio error 3.8 Permanent magnetisation 3.18 Permanent magnet moving coil instrument 2.12 Permanent Magnet Moving Coil (PMMC) 2.12 Permeameters 12.19 Phantom loading 8.15 Phase-angle error 3.32, 8.9 Phase distortion 13.36 Phase Modulation (PM) 17.10 Phase noise 17.5 Phase Shift Keying (PSK) 17.12 Phosphor-bronze springs 7.9 Phosphors 15.18 Phosphor screen 9.1 Photoelectric transducers 11.24 Pierce oscillator 13.16 Piezoelectric transducers 11.26 PIN Diodes 18.5 Pivot and jewel bearings 2.4 Plasma Display Panel (PDP) 15.26 PLC programming terminal 16.8 Polar potentiometer 5.13 Portable-type CT 3.16 Positive feedback 13.1 Potential terminals 4.19 Potential transformers or PTs 3.26, 7.35 Potentiometer 5.1 Potentiometer method for measuring low resistance 4.23 Power amplifier 9.7 Power in band 17.3 Power measurement in AC Circuits 7.6 Power measurement in DC Circuits 7.1 Power measurement in polyphase systems 7.25 Power measurement using thermistor 17.16 Power measurement with instrument transformers 7.35 Power meter 18.7 Power supply 16.6 Precision 1.16 Pressure coil 2.33, 7.9 Pressure measurement 11.19 Price’s guard-wire method 4.28 Primary standards 1.2 Primary transducer 11.19 Programmable Logic Controllers (PLCs) 16.1 Program scan time 16.11 Pulse generators 13.18 Pulse width modulator 14.20 Q Q factor 6.8 Quality factor 14.6 Quantisation 14.14 Quantisation levels 14.14 Quartz crystal oscillator 10.16 R R-2R Ladder DAC 14.21 Radio frequency 17.1 Radio frequency Spectrum Analyser 17.5 Ramp/Counter 14.16 Ramp-Type DVM 10.10 Ramp voltage 9.6 Random error 1.19, 1.21 Range 14.19 Ratio arms 4.16 Ratio error 3.7, 3.32 RC Oscillator 13.10 Reactive Power Measurements 7.33 Read-Only Memory (ROM) 9.20 Recording instruments 1.13 Rectifier-type instruments 2.43 Reference cell 5.2 Reference junction 11.15 Relative error 3.18 Remote I/O 16.10 Repeatability 11.2 Residual magnetism 1.3 Residual reformation 11.2 Resistance standards 1.16 Resistance strain gauges 11.5 Resistance temperature detectors 11.11 Resistance thermometers 11.11 Resistive transducers 11.20 Resolution 2.5 Resolution Bandwidth 17.4 Resonance 13.3, 13.4 RF Analysers 17.7 RF communication system 17.15 RF network analyser 17.7 RF signal generator 13.28 RF Voltage and Power Measurement 17.16 Ribbon suspension 11.2 Roll Off 14.6 S Sample-and-hold (S/H) 9.20 Sampling 14.14 Sampling oscilloscope 9.17 Sawtooth waveform 9.6 Scalar Network Analyser (SNA) 17.7 Schering bridges 6.20 Schmitt trigger 13.24 Secondary emission electrons 9.19 Secondary instruments 1.13, 2.1 Secondary standards 1.2 Secondary transducer 11.19 Seebeck voltage 11.14 Self-inductance 6.4 Self-operated instruments 1.15 Sensitivity 1.16, 2.20 Sensitivity of a full-wave rectifier circuit 2.44 Sensitivity of a half-wave rectifier circuit 2.44 Sensitivity of rectifier-type instrument 2.43 Sensor 11.1 Sensors and transducers 14.5 Series magnet 7.22 Series-type ohmmeter 4.2 Settling time 10.4, 8.5 Seven Segment Display 15.20 Shading bands 8.5 Shading coil 8.9 Shading loop 8.12 Shading vane for friction compensation 8.12 Shape of scale in electrodynamometer-type wattmeter 7.12 Shape of scale in series ohmmeters 4.4 Shape of scale in shunt ohmmeters 4.7 Shields 7.18 Shunt 2.18 Shunt magnet 7.22 Shunts and multipliers 3.1 Signal conditioning 14.5 Signal generators 10.14 Sine wave generator 13.24 Single-point and multi-point recorders 15.5 Sinusoidal oscillators 13.2 Space frequency 17.12 Space loss 17.2 Spectrum analyser 13.37, 17.6 Spectrum analysis 17.5 Speed of response 1.17 Spindle 2.5 Spiral spring 2.3, 7.9 Spontaneous emission 18.4 Spring control 2.6 Square wave generator 13.18 Standard arm 4.16 Standard cell 1.4 Standardisation 5.2 Standardize the potentiometer 5.2 Standard of measurement 1.2 Standard resistor 5.7 Standard variable resistance 4.14 Statement list 16.12, 16.16 Storage 10.3 Strain gauges 11.5 Stray capacitance 7.16 Strip chart recorder 15.2 Substitution method for measuring resistance 4.14 Successive approximation 14.15 Super-Heterodyne analyser 17.6 Surface leakage 4.24 Suspension 2.4, 7.9 Swamping Resistance 2.15 Sweep frequency generator 13.29 Sweep generator 9.7, 13.29 Synchronisation 9.7 Systematic error 1.19, 1.21 T Talker 14.26 Taut suspension 2.4 Temperature coefficient of resistance 11.11 Temperature effects 8.13 Temperature errors 7.19 Temperature sensitivity 10.4 Temperature transducers 11.11 Testing of specimens 12.18 THD 13.36 THD+N 14.22 Thermal Dot Array Recorders 15.10 Thermal emfs 11.17 Thermistors 11.14, 17.16 Thermocouple 2.39, 17.16 Thermocouple instrument 2.41 Thermometer Coded DAC 14.21 Three-Wattmeter Method 7.27 Time and frequency standards 9.1 Time base 10.14 Timers 16.3 Tone generator 2.6 Torque/weight ratio 2.6, 11.1 Total harmonic distortion 13.36 Total internal reflection 18.1 Total percentage Harmonic Distortion (THD) 17.5 Transducer 10.1 Transistorised Voltmeter (TVM) 9.8 Triangular wave generator 13.22 Trigger circuit 9.8 Triggered Sweep 6.1 True RMS voltmeter 2.46 Tuned detector 3.31 Turns ratio 7.27 U Ultraviolet Recorders 15.9 Underdamped 2.3 Unit of energy 8.1 V Vacuum Tube Voltmeter (VTVM) 10.1 Vane 8.12 Varley Loop Test 4.35 Vertical deflection plates 9.2 Vibration galvanometers 6.1 VNA 17.8 Voltage coil 7.5 Voltage-controlled-oscillator 13.27 Voltage Controlled Oscillator (VCO) 13.29 Voltage stability 14.17 Voltage standards 1.3 Voltmeter-ammeter method for measuring low resistance 4.19 Voltmeter-ammeter method for measuring resistance 4.11 Voltmeter multipliers 2.19 W Wagner earth device 6.26 Wave analyser 13.33 Waveguides 18.1 Weston frequency meter C.1 Wheatstone bridge 4.15, 9.7 Wideband preamplifier 13.13 Wien Bridge Oscillators 6.20 Wien’s bridge 6.22 Wireless communication 17.2 Wireless communication system 17.1 Working standards 3.14 X X-Y Recorder 15.7 ... for the course in electrical and electronics measurements and instrumentation It presents a comprehensive treatment of the subject of electrical and electronics measurements and instrumentation. .. as for some of the derived mechanical and electrical units The classifications of standards are International standards Primary standards Secondary standards Working standards Current standards Voltage standards Resistance standards... undergraduate course in electrical and electronics measurements Since the basic concepts cut across disciplines—such as electrical, mechanical, electronics, instrumentation and control engineering—this