Electrical and Electronics Measurements and Instrumentation PDF

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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 ...

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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

1. 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

2. 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

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

12.3 The Ballistic Galvanometer 12.4 Fluxmeter 12.5 Uses of Ballistic Galvanometer and Fluxmeter 12.6 Measurement of Flux Density 12.7 Measurement of Magnetising Force (H) 12.8 Determination of Magnetising Curve 12.9 Determination of Hysteresis Loop 12.10 Testing of Specimens in the Form of Rods or Bars 12.11 Permeameters 12.12 Measurement of Magnetic Leakage 12.13 Magnetic Testing with Alternating Current 12.14 Bridge and ac Potentiometer Methods 12.15 Magnetic Shielding Exercise

13. Signal Generators and Analysers 13.1 Introduction 13.2 Oscillators 13.3 Hartley Oscillator 13.4 Colpitts Oscillators 13.5 The RC Oscillator 13.6 Wien Bridge Oscillators 13.7 Crystal Oscillators 13.8 Pierce Oscillator 13.9 Microprocessor Clocks 13.10 Square Wave and Pulse Generators 13.11 Triangular Wave Generator 13.12 Sine-Wave Generator 13.13 Function Generators 13.14 RF Signal Generator 13.15 Sweep Frequency Generator 13.16 Wave Analyser 13.17 Harmonic Distortion Analysers

13.18 Spectrum Analyser Exercise

14. Data Acquisition System 14.1 Introduction 14.2 Basic Components of Data Acquisition Systems 14.3 Components of a Typical PC-based Data Acquisition System 14.4 Analog Input Subsystem 14.5 Analog Output Subsystem 14.6 Digital Input and Output Subsystem 14.7 IEEE 488 Interface Exercise

15. Recording, Storage and Display Devices 15.1 Introduction 15.2 Analog Recorders 15.3 Digital Recorders 15.4 Display System Exercise

16. Programmable Logic Controllers 16.1 Introduction 16.2 Advantages of PLCs 16.3 The Control Program 16.4 Function of each Part in PLC 16.5 Hardware of PLC 16.6 System Addressing 16.7 PLC Operation and Program Scan 16.8 Implementation of Control Programs in PLC 16.9 More in Ladder Logic Exercise

17. Microwave and RF Measurement 17.1 Introduction to RF and Wireless Communication System 17.2 Radio Frequency and Microwave Spectral Analysis

17.3 Radio Frequency Spectrum Analyser 17.4 RF Scalar and Vector Network Analyser 17.5 Modulation 17.6 Communication Systems 17.7 RF Voltage and Power Measurement Exercise

18. Fibre Optic Measurements 18.1 Introduction 18.2 How does an Optical Fibre Work? 18.3 Sources and Detectors 18.4 Fibre Optic Power Measurement Exercise

Appendix A Table of SI Units Appendix B Number Systems Appendix C Westen Frequency Meter Solved Sample Question Papers Index

Preface Overview This book can be used as a textbook 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 taught to the undergraduate students of B.Tech/BE in Electrical Engineering, Electrical and Electronics Engineering, Instrumentation Engineering, and allied branches. The book thus aims at maintaining balance between these diverse fields of engineering disciplines by drawing examples from various applications. The prerequisite on the part of the reader is that he or she should have had introductory courses on linear algebra, basic calculus, vector/phasor analysis, transform theory, circuit analysis and elementary mechanics. For the students’ interest, appendices on number systems and unit conversions are added at the end. Aim While conceptualising the text, the authors felt that the scope and method of treatment could, with advantage, be augmented to suit the requirements of various branches of engineering. Owing to the rapid advancements taking place in modern electrical and allied industries, and their interconnection with power systems, the subject of electrical and electronics measurements is gaining an ever-increasing importance. About the Book As a subject of study, electrical measurement is one of the more traditional fields of electrical and allied engineering disciplines. However, with progress in technology and manufacturing expertise, measurements of physical parameters have gained new heights in terms of state-of-the-art concepts and technologies. This book aims at bridging traditional concepts with modern technologies of electrical and electronics measurements and instrumentation. The text is designed for an undergraduate course in electrical and electronics measurements. Since the basic concepts cut across disciplines—such as electrical, mechanical, electronics, instrumentation and control engineering—this book presents a proper balance between theoretical and analytical approach, as well as practical illustrations along with computational approach for solving various kinds of numerical problems. Some of the subjects dealt with are essentially mathematical in nature, and cannot be treated otherwise, but the mathematics throughout the book has been kept as simple as possible so that it is followed easily by most readers. The theory of most of the measurement techniques and measuring instruments has been dealt with in sufficient detail, but in most cases concise forms have been used for such theoretical discussions, so that readers may skip them, if desired, and consider only the resulting expressions. Photographs of real systems have been used in places where schematic representation needed to be augmented. The main theme of this book has been to cater to undergraduate students. All topics in different chapters have been developed with ample and adequate detail without subjecting students to unwanted complicacies. As a textbook, this contribution is expected to help

students not only in building up their knowledge of physical concepts of the systems described, but also as a ready and concise reference. Salient Features Coverage bridges traditional concepts with modern technologies in the subject area Comprehensive discussions on electronic measurement systems and related components including analysers, data acquisition systems, etc. Special-purpose measurements and applications such as magnetic measurements and fibre optic measurements covered Dedicated chapter on Sensors and Transducers Inclusion of real-life photographs to augment schematic diagrams wherever necessary Solved question papers from 9 universities Rich pedagogy • Illustrations: 400 • Solved Examples: 100 • Objective-type Questions: 236 • Short-Answer-Type Questions: 164 • Long-Answer-Type Questions: 119 Chapter Organisation The entire text is organised into 18 chapters. Chapter organisation has been primarily based on the electrical and electronic measurement syllabi in BE/B.Tech undergraduate courses of universities around the country. The outline of the book can be organised in the following four major parts: 1. General concepts of measurement 2. Electrical measurement techniques and classical measuring instruments 3. Modern measurement techniques and instruments 4. Brief concepts of sensors and transducers 5. Electronic measurement systems and related components including signal generators, analysers, data acquisition systems, storage and display devices and programmable logic controllers 6. Applications of the concepts of electrical and electronic measurement systems in special-purpose measurements including magnetic measurements, fibre optic measurements, RF and microwave measurements. Within this framework, a more in-depth breakdown can be obtained from the table of contents. Detailing in the table of content will be useful for the instructors and students to select parts of the text that might be appropriate for the specific need at hand. In places where illustrations and explanations have been summarised, the adequate list of reference at the end will enable enthusiastic readers to probe further. The fluid flow of text dealing

with different topics has been well thought out by the authors who have several years of experience in teaching the subject directly to undergraduate students. Illustrations, examples, questions, highlights, exercises, numerical problems are extremely relevant and appropriate for students as well as instructors. The main strength of the book thus is its strong focus towards students’ readability and understanding with the scope for independent study and problem-solving skill development. The authors are confident that the depth of this book has been judiciously developed so that students not only treat this as a textbook, but, in addition, can also gather enough practical and theoretical knowledge to appear in national-level competitive examinations and interviews. Web Supplements The text is supplemented with an exhaustive Online Learning Center, which can be accessed at https://www.mhhe.com/purkait/eemi It contains PowerPoint lecture slides and the Solution Manual. Acknowledgements We are thankful to all those who have directly or indirectly helped us in bringing out this book. First, we would like to thank the reviewers who through various instances have provided comments that have shaped this book. Their names are given below: Nilesh Chaurasia

Sri Vaishnav Institute of Technology and Science, Indore, Madhya Pradesh

Saurabh Basu

GLA University, Mathura, Uttar Pradesh

Praveen Tiwari

IMIT College, Meerut, Uttar Pradesh

S B L Seksena

National Institute of Technology (NIT) Jamshedpur, Jharkhand

Suvendu Naryan Mishra

Veer Surendra Sai University of Technology (VSSUT), Burla, Odisha

Samir Ekbote

Datta Meghe College of Engineering, Navi Mumbai, Mumbai, Maharashtra

V G Sarode

Xavier Institute of Engineering, Mumbai, Maharashtra

C D Kapse

Watmull Institute of Engineering and Computer Technology, Mumbai, Maharashtra

Ruban N

Vellore Institute of Technology (VIT) University, Vellore, Tamil Nadu

Subhash Krishnamoorthy

National Institute of Technology (NIT), Calicut, Tamil Nadu

R S Varadhan

ICFAI Institute of Technology & Science, Hyderabad, Andhra Pradesh

K E Srinivas Murthy

Sri Venkateswara Institute of Technology, Ananthapur, Andhra Pradesh

C H Madhuri

Sri Indu College of Engineering, Hyderabad, Andhra Pradesh

Thanks are also due to the staff at McGraw Hill Educa...