PRINCIPLES OF ELECTRICAL MEASUREMENT
PRINCIPLES OF ELECTRICAL MEASUREMENT
Sensors SeriesSenior Series Editor: B E JonesSeries Co-Editor: W B Spillman, JrNovel Sensors and SensingR G JacksonHall Effect Devices, Second EditionR S PopovićSensors and their Applications XIIEdited by S J Prosser and E LewisSensors and their Applications XIEdited by K T V Grattan and S H KhanThin Film Magnetoresistive SensorsS TumanskiElectronic Noses and Olfaction 2000Edited by J W Gardner and K C PersaudSensors and their Applications XEdited by N M White and A T AugoustiSensor MaterialsP T Moseley and J CrockerBiosensors: Microelectrochemical DevicesM Lambrecht and W SansenCurrent Advances in SensorsEdited by B E Jones
Series in SensorsPRINCIPLES OFELECTRICAL MEASUREMENTS TumanskiWarsaw University of TechnologyWarsaw, PolandNew York London
IP832 Discl.fm Page 1 Wednesday, November 23, 2005 1:02 PMPublished in 2006 byCRC PressTaylor & Francis Group6000 Broken Sound Parkway NW, Suite 300Boca Raton, FL 33487-2742 2006 by Taylor & Francis Group, LLCCRC Press is an imprint of Taylor & Francis GroupNo claim to original U.S. Government worksPrinted in the United States of America on acid-free paper10 9 8 7 6 5 4 3 2 1International Standard Book Number-10: 0-7503-1038-3 (Hardcover)International Standard Book Number-13: 978-0-7503-1038-3 (Hardcover)Library of Congress Card Number 2005054928This book contains information obtained from authentic and highly regarded sources. Reprinted material isquoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable effortshave been made to publish reliable data and information, but the author and the publisher cannot assumeresponsibility for the validity of all materials or for the consequences of their use.No part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic,mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, andrecording, or in any information storage or retrieval system, without written permission from the publishers.For permission to photocopy or use material electronically from this work, please access www.copyright.com(http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC) 222 Rosewood Drive,Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organization that provides licenses and registrationfor a variety of users. For organizations that have been granted a photocopy license by the CCC, a separatesystem of payment has been arranged.Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used onlyfor identification and explanation without intent to infringe.Library of Congress Cataloging-in-Publication DataTumanski, Slawomir.Principles of electrical measurement / by Slawomir Tumanski.p. cm.-- (Series in sensors)Includes bibliographical references and index.ISBN 0-7503-1038-31. Electric measurements. 2. Electronic measurements. 3. Signal processing. I. Title. II. Sensorsseries.TK275.T75 2005621.37--dc222005054928Visit the Taylor & Francis Web site athttp://www.taylorandfrancis.comTaylor & Francis Groupis the Academic Division of Informa plc.and the CRC Press Web site athttp://www.crcpress.com
ContentsPrefaceix1. Introduction to Measurements12. Fundamentals of Electrical Measurements132.1. Main Terms and Definitions2.1.1. Basic terms of measurement technique2.1.2. The main methods of measurements2.2. Uncertainty of Measurements2.2.1. Errors, uncertainty, and reliability of signal processing2.2.2. Basic statistical terms and concepts2.2.3. Methods of evaluation and correction of the uncertaintyrelated to limited accuracy of measuring devices2.2.4. The estimation of uncertainty in measurements2.3. Standards of Electrical Quantities2.3.1. Standards, etalons, calibration and validation2.3.2. The standards of electrical quantities referred tothe physical phenomena and laws2.3.3. Material standards of electrical quantities2.3.4. The reference multimeters and calibratorsReferences131318262634586369713. Classic Electrical Measurements733.1. Indicating Measuring Instruments3.1.1 Electromechanical instruments versus digitalmeasuring systems3.1.2. The moving coil meters3.1.3. The moving iron meters3.1.4. Electrodynamic meters – wattmeters3.1.5. Induction type watt-hour meters3.2. Recording and Displaying Measuring Instruments3.2.1. Fundamentals of oscilloscopes3.2.2. Recorders and data storage devices3.3. Bridge Circuits3.3.1. Balanced and unbalanced bridge circuits3.3.2. Null-type DC bridge circuits73V405257577374818286888893949496
VIPRINCIPLES OF ELECTRICAL MEASUREMENTS3.3.3. The AC bridge circuits3.3.4. The transformer bridge circuits3.3.5. The unbalanced bridge circuits3.3.6. The alternatives for bridge circuits – Anderson Loop3.4. Potentiometers and ComparatorsReferences991041071121141184. Processing of the Analogue Measurement Signals1214.1. Signal Conditioning4.1.1. Analogue measurement signals4.1.2. Conditioning of resistance, capacitance and inductance4.1.3. AC/DC conversion4.1.4. Voltage to frequency conversion4.2. Amplification of the Signals4.2.1. Differential, operational and instrumentation amplifiers4.2.2. Isolation amplifiers4.2.3. Amplifiers of very small DC signals4.2.4. Amplifiers of very small AC signals4.2.5. Amplifiers of very large input resistance (electrometers)4.2.6. The function amplifiers4.3. Negative Feedback in the Measuring Technique4.4. The Improvement of the Quality of the Analogue Signals4.4.1. The noises and interferences of the analogue signals4.4.2. The connection of the measuring signal to the amplifier4.4.3. The analogue filtering of the 1611691791791841912015. Digital Processing of the Measurement Signals2055.1. Analogue-to-Digital Converters5.1.1. Sampling, quantization and coding of signals5.1.2. Analogue-to-digital converters ADC5.1.3. The main specifications of analogue-to-digital converters5.2. Digital-to-Analogue Converters5.2.1. The reconstruction of the analogue signal5.2.2. The digital-to-analogue converters DAC5.2.3. The main specifications of digital-to-analogue converters5.3. Methods and Tools of Digital Signal Processing5.3.1. The main terms of digital signal processing5.3.2. The Discrete Fourier Transform DFT and Fast FourierTransform FFT5.3.3. Short-time Fourier Transform and Wavelet transform5.3.4. Digital filters205205218234238238242247249249259268275
CONTENTSVII5.4. Examples of Application of Digital Signal Processing inMeasurements5.4.1. The spectral analysis5.4.2. Digital signal synthesis5.4.3. Improvement of the signal quality and the signal recovery5.5. Digital Measuring Instruments5.5.1. Digital multimeters and frequency meters5.5.2. Digital oscilloscopes5.5.3. Digital measurement of power and energy5.6. Intelligent Data Analysis5.6.1 The artificial intelligence in measurements5.6.2. The adaptive filters5.6.3. Artificial neural networks5.6.4. Fuzzy 13403446. Computer Measuring Systems3496.1 Introduction6.2. Input Circuits of the Measuring Systems6.2.1. Circuits for data conditioning and acquisition6.2.2. The sensors with built-in interface – intelligent sensors6.2.3. Analogue and digital transmitters6.2.4. Data loggers6.2.5. IEEE P1451 standard – smart sensors6.3. Data Acquisition Circuits – DAQ6.3.1. Plug-in data acquisition board6.3.2. External data acquisition board6.4. Data Communication in Computer Measuring Systems6.4.1. Interfaces, buses and connectors6.4.2. Serial interfaces: RS-232C and RS-4856.4.3. Serial interfaces: USB and FireWire6.4.4. Parallel GPIB interface (IEEE-488/IEC-625)6.4.5. Wireless interfaces: IrDA, Bluetooth and WUSB6.4.6. Mobile telephony systems GSM and UMTS as a toolfor data transfer6.4.7. Radio data acquisition and transfer6.4.8. Computer systems using Ethernet and Internet6.4.9. Dedicated interfaces: CAN, I2C, MicroLAN, SDI-126.4.10. HART interface and the 4 – 20 mA standard6.4.11. Industrial communication standards – Fieldbus, Profibus,SCADA6.4.12. Modular systems – VXI, PXI6.4.13. Standard command for measuring devices – 82385389392396400401406408
VIIIPRINCIPLES OF ELECTRICAL MEASUREMENTS6.5. Measuring Systems Basing on the Signal Processors6.5.1. Microcontrollers and signal processorsin measuring technique6.5.2. Microinterfaces – SPI and UART6.6. Virtual Measuring Systems6.6.1. What is the virtual measuring device?6.6.2. TestPoint6.6.3. Agilent VEE Pro6.6.4. LabVIEW of National Instruments6.7. The Examples of Computer Measuring Systems6.7.1. The measuring system for testing of magnetic materials6.7.2. The arbitrary wave excitation systems6.7.3. The scanning device for magnetic field 449452Symbols used in the BookAbbreviations used in the BookIndex455457461
PrefaceIn libraries and bookshops we can find various books on electricalmeasurements 1 . Most of them describe various aspects of electricalmeasurements: digital or analogue techniques, sensors, data acquisition, dataconversion, etc. However, it can be difficult to find a book that includes acomplete guide on the techniques used in taking electrical measurements.The reason for this is rather obvious –modern measuring requires knowledgeof many interdisciplinary topics such as computer techniques, electronics,signal processing, micro- and nanotechnology, artificial intelligencemethods, etc. It is practically impossible for one author to know and explainall these subjects. Therefore, there are frequently available books called“Handbook of ” written by dozens of co-authors. Unfortunately, such booksare mainly more conglomerates of many encyclopaedia entries of unequallevels than comprehensive and compact knowledgeable books.The other aspect of this problem is that the progress in measuringtechniques is very fast, with every year bringing new developments. It isreally difficult to catch the state of the art in measurements. It is much easierto gather knowledge on a particular subject in the form of a monographfocused on a special problem. But on the other hand, students and industryengineers look for comprehensive books that are easy to understand and mostof all include recent developments, such the computer measuring systems orvirtual measuring methods. I lecture on electrical measurements to studentsof electrical engineering, robotics and informatics. To tell the truth I couldnot find a suitable book on the whole subject and therefore I decided to writeone myself. Last year I “tested” this book on students and the results werequite promising. Most of the students understood the electrical measurementsand what most importantly, they found that this subject was interesting, andeven fascinating.Let us look at modern measurement techniques, the present state and thefuture perspectives. There is no doubt that the future is reserved for computermeasuring systems. It is no wonder that today, when a simple electric shaveris supported by a microcontroller that the measuring instruments are also1A non-exhaustive list of market available books on measurements is included at the endof this preface.IX
XPRINCIPLES OF ELECTRICAL MEASUREMENTScomputerized. Recently, computer measuring systems have become maintools and the subject of research. The result is that many important topics,discussed in this book as “Classic Electrical Measurements” are today on theperiphery of interest. However knowledge of these subjects is important tounderstand the principles of modern measuring instruments.Other consequence of the development of computer and microelectronicssupported measuring systems is that they are now also available to nonspecialists. Today, what was reserved exclusively in past, measuring devicesas high quality analogue to digital converters or amplifiers, are now availableto all at modest prices. User friendly software such as LabVIEW helps in thedesign of sophisticated measuring instruments. So-called intelligent sensorsare today designed in “plug and play” technology, ready to connect intoworldwide computer networks. Thus currently, the measurement technique isopen to everyone (including persons far from electrical engineering) and it isimportant to show them, how to perform the measurements correctly. Thisbrings us to the fundamental question: which knowledge aboutmeasurements is indispensable?After discussing with many university colleagues, practicing industryengineers and of course students, the proposal of contents for suchindispensable subject was formulated. But it appeared that to present suchsubjects more than a thousand pages book was advisable. Therefore, thewhole programme was divided into two clearly separated parts: “Principlesof Electrical Measurements” and “Application of Electrical Measurements inScience, Industry and Everyday Life”. This first part is presented in thisbook.I understand the “Principles of Electrical Measurements” as the wholeknowledge, common for all types of electrical measurements. These commonsubjects include most of all signal processing techniques (digital and as wellanalogue), classic measurement techniques, methods of estimation ofaccuracy and uncertainty of measurement results, data acquisition andsignal conditioning, application of computers and digital signal processorsin measurement and virtual measurements techniques. When such subjectsare understood (for example, after reading this book, I hope) it should bemore easy to adapt to the more practical subjects: “Application of ElectricalMeasurements” – sensors, measurements of electrical and non-electricalquantities, non-destructive testing and material evaluation, design ofmeasuring instruments, etc.).This book is divided into three main parts. In the first one (Chapters twoand three) the fundamentals and classic electrical methods are described(main terms and methods, standards and measurement uncertainty). Thesecond part (Chapters four and five) are devoted to signal processing –analogue and digital. And the last part (Chapter six) informs about computermeasuring systems. Taking into account the state of the arts techniques and
XIPREFACEperspectives of electrical measurements presented above, we understand whythe “classical part” occupies only about quarter of the book while the “digitalsignal processing and computer measuring systems” fill more than half of it.This book is addressed mainly to students, but the proposed materialshould be also useful for practicing engineers. As was earlier mentioned, thisbook was “tested” on several groups of students of Warsaw University ofTechnology. I would like to thank many colleagues from that University forvaluable discussions and remarks. I would especially like to thank professorsJerzy Barzykowski, Marek Stabrowski, Zygmunt Warsza, Dr Stan Zurek(from Cardiff University) and Ph.D. student Slawomir Baranowski.Slawomir TumanskiMost important books related to Electrical MeasurementsAnalog Devices 2004 Data Conversion Handbook, NewnesAnderson N.A. 1997 Instrumentation for Process Measurement and Control,CRC PressAusterliz H. 2002 Data Acquisition Techniques using PCs, Academic PressBaican R., Nesculescu D.S. 2000 Applied Virtual Instrumentation,Computational MechanicsBattigha N.E. 2003 The condensed Handbook of Measurement and Control, ISAInstrumentationBentley J.P. 2004 Principles of Measurement Systems, Prentice HallBolton W. 2001 Newnes Instrumentation and Measurement Pocket Book,NewnesBoyes W. 2002 Instrumentation Reference Book, Butterworth-HeinemannBrignel J. White N. 1996 Intelligent Sensor System, IOP Publ.Dally J.W., Riley W.F., McConnell K.G. 1993 Instrumentation for EngineeringMeasurements, John Wiley & SonsDoebelin E.O. 2003 Measurement Systems, McGraw-HillDunn W.C. 2005 Introduction to Instrumentation, Sensors, and Process Control,Artech HouseDyer S.A. 2001 Wiley Survey of Instrumentation and Measurements, IEEEComputer SocietyElgar P. 1998 Sensors for Measurement and Control, Prentice HallEren H. 2003 Electronic Portable Instruments: Design and Application, CRCPressFraden J. 2003 Handbook of Modern Sensors, SpringerFrank R. 2000 Understanding Smart Sensors, ArtechGardner J.W., Varadan V.K., Awadelkavim O.A. 2001 Microsensors, MEMSand Smart Devices, Wiley & SonsHughes T.A. 2002 Measurement and Control Basic, ISA-Instrumentation
XIIPRINCIPLES OF ELECTRICAL MEASUREMENTSJames K. 2000 PC Interfacing and Data Acquisition: Techniques forMeasurements, Instrumentation and Control, NewnesKester W. 2005 Data Conversion Handbook, Butterworth-HeinemannKester 2003 Mixed Signals and DSP Design Techniques, NewnesKlaasen K.B. 1996 Electronic Measurement and Instrumentation, CambridgeUniversity PressKularatna N. 2002 Digital and Analogue Instrumentation Testing andMeasurement, IEELiptak B.G. 2003 Instrument Engineering Handbook: Process Measurement andAnalysis, CRC PressMorris A.S 2001 Measurements and Instrumentation Principle, ButterworthHeinemanMorris A.S 1996 The Essence of Measurement, Prentice HallNawrocki W. 2005 Measurement Systems and Sensors, ArtechNorthrop R.B. 1997 Introduction to Instrumentation and Measurements, CRCPressPallas-Areny R., Webster J.G. 1991 Sensors and Signal Conditioning, JohnWiley & SonsPark J., Mackay S. 2003 Practical Data Acquisition for Instrumentation andControl, NewnesPaton B.E. 1998 Sensors, Transducers, LabVIEW, Prentice HallPotter R.W. 1999 The Art of Measurement, Prentice HallPutten van A.F. 2003 Electronic Measurement Systems: Theory and Practice,IOP Publ.Ramsey D.C. 1996 Principles of Engineering Instrumentation, ButterworthHeinemannRathore T.S. 2004 Digital Measurement Techniques, CRC PressRomberg T.M., Ledwige T.J., Black J.L. 1996 Signal Processing for IndustrialDiagnostics, John Wiley & SonsSchnell L. 1993 Technology of Electrical Measurements, John Wiley & SonsSinclair I. 2001 Sensors and Transducers, NewnesSwanson D.C. 2000 Signal Processing for Intelligent Sensor Systems, MarcelDekkerSydenham P.H. (Ed) 2005 Handbook of Measuring System Design, John Wiley& SonsTaylor H.R. 1997 Data Acquisition for Sensor Systems, SpringerTran Tien Lang 1987 Electronics of Measuring Systems, John Wiley & SonsTurner J.D., Hill M. 1999 Instrumentation for Engineers and Scientists, OxfordUniversity PressWebster J.G. 1998 Measurements, Instrumentation and Sensors Handbook, CRCPressWebster J.G (Ed) 2004 Electrical measurement, Signal Processing and Display,CRC PressWilson J.S. 2004, Sensor Technology Handbook, Newnes
1Introduction to MeasurementsThe main person of the Molier’s comedy “The Bourgeois Gentleman 1 ”Monsieur Jourdain states with amazement “By my faith! For more than fortyyears I have been speaking prose without knowing about it.”. Probablymany of the readers would be also surprised by the information that theyperform measurements almost all the time and everywhere without knowingabout it. When we say “it is cold today” we describe the result of ameasurement carried out by our senses (receptors). Such measurement isperformed in a subjective way - another person could state in the sameconditions that it is not cold. But generally we estimate the temperature bycomparison with the temperature memorized as a reference one. Thus weperformed the measurement.Furthermore, when we say “I do not feel well today” we describe theresults of the analysis of the state of our organism. Our receptors tested theparameters: blood pressure, body temperature, pulse, level of adrenaline, etc.as incorrect. The measuring system in our body operates very similarly to acomputer measuring systems used for instance in the industry. The receptors(the sensors) determine the value of many quantities: light, sound, smell,temperature, etc. The results of the sensing are transmitted to the brain as theelectrical signals by the interface consisting of billions of nervous fibers 2 .Our brain acts as a central com
5.2. Digital -to -Analogue Converters 238 5.2.1. The reconstruction of the analogue signal 238 5.2.2. The digital-to-analogue converters DAC 242 5.2.3. The main specifications of digital-to-analogue converters 247 5.3. Methods and Tools of Digital Signal Processing 249 5.3.1. The main terms
Electrical Infrastructure includes an electrical installation, electrical equipment, electrical line or associated equipment for an electrical line. 1.9 Electrical installation As per the Electrical Safety Act 2002 (s15) (a) An electrical installation is a group of items of electrical equipment that—
P100 Partial Plumbing Plan ELECTRICAL E001 Electrical Notes E002 Electrical Symbols E003 Energy Compliance ED100 Electrical Demo Plan E100 Electrical Lighting Plan E200 Electrical Power Plan E300 Electrical One-Line E400 Electrical Schedules The Addenda, if any, are as follows: Number Date Pages . .
mental principles of measurement which underlie these studies. The book treats measurement as a coherent and integrated subject by presenting it as the study of measurement systems. A measurement system is
ELECTRICAL MEASUREMENT LABORATORY MODULE 2020 5 MODULE 2 IMPEDANCE MEASUREMENT I. OBJECTIVE 1. To know LCR Meter and its function 2. To know the construction of LCR Meter and how LCR Meter works II. BASIC THEORY LCR meter is an electronic electrical measurement to measure resistance, inductance and capacitance value.
JIS are possible. Moreover, the 6240B is capable of high-precision contact resistance measurement that cancels thermal EMF generated on metal contact surfaces. Source and Measurement Function The source and measurement functions are selectable from voltage source, current source, voltage measurement, cur-rent measurement and resistance measurement.
Measurement method: TN measurement of Ammonium Sulfate Aqueous Solution, prepared nitrogen concentration 10 mg/L Measurement results: TN 9.91 mg/L (C.V. 0.30 %) Example of TOC Measurement of Nickel Plating Solution Analysis instrument: TOC-LCPH Measurement method: TOC measurement of
Type of Measurement Tool for Measurement Unit of Measurement Length Triple Beam Balance, Electronic Balance 3 Milliliter (mL), Liter (L), cm Temperature Spring Scale C. Metric System – 1. Which measurement would you use to measure the following items? A. Length of a piece of paper: B. Volume of a soda bottle: C. Your mass: D.
positive. The unit of electrical charge is the coulomb (symbol: C). Electrical current An electrical current is the movement of negative electrical charges (electrons) through a conductor (electrical wire, metal foil, etc.). In an electrical circuit, the current flows from the point where the electrical potential is highest to the point where .
