Fundamentals of Instrumentation and Measurement

555 Pages·2007·8.543 MB·English

by  Dominique Placko

Fundamentals of Instrumentation and Measurement
This page intentionally left blank
Fundamentals of
Instrumentation
and Measurement

Edited by
Dominique Placko
First published in France in 2000 by Hermès Science Publications in two volumes entitled
“Mesure et Instrumentation”
Published in Great Britain and the United States in 2007 by ISTE Ltd
Apart from any fair dealing for the purposes of research or private study, or criticism or
review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may
only be reproduced, stored or transmitted, in any form or by any means, with the prior
permission in writing of the publishers, or in the case of reprographic reproduction in
accordance with the terms and licenses issued by the CLA. Enquiries concerning reproduction
outside these terms should be sent to the publishers at the undermentioned address:
ISTE Ltd ISTE USA
6 Fitzroy Square 4308 Patrice Road
London W1T 5DX Newport Beach, CA 92663
UK USA
www.iste.co.uk

© ISTE Ltd, 2007
© HERMES Science Europe Ltd, 2000

The rights of Dominique Placko to be identified as the author of this work have been asserted
by him in accordance with the Copyright, Designs and Patents Act 1988.

Library of Congress Cataloging-in-Publication Data

[Mesure et instrumentation. English]
Fundamentals of instrumentation and measurement/edited by Dominique Placko.
p. cm.
Includes index.
ISBN-13: 978-1-905209-39-2
1. Mensuration. 2. Engineering instruments. 3. Scientific apparatus and instruments.
4. Detectors. I. Placko, Dominique.
T50.M394 2006
620'.0044--dc22
2006020964

British Library Cataloguing-in-Publication Data
A CIP record for this book is available from the British Library
ISBN 13: 978-1-905209-39-2
Printed and bound in Great Britain by Antony Rowe Ltd, Chippenham, Wiltshire.
Table of Contents
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii

Chapter 1. Measurement Instrumentation. . . . . . . . . . . . . . . . . . . . . 1
Mustapha NADI
1.1. General introduction and definitions. . . . . . . . . . . . . . . . . . . . . 1
1.2. The historical aspects of measurement. . . . . . . . . . . . . . . . . . . . 2
1.3. Terminology: measurement, instrumentation and metrology. . . . . . . 4
1.4. MIM interactions: measurement-instrumentation-metrology. . . . . . . 4
1.5. Instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.6. Is a classification of instruments possible? . . . . . . . . . . . . . . . . . 7
1.6.1. Classification of instruments used in cars. . . . . . . . . . . . . . . . . 9
1.7. Instrument modeling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.7.1. Model of a measurement instrument. . . . . . . . . . . . . . . . . . . 11
1.7.2. Load effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.7.3. Estimating load effects. . . . . . . . . . . . . . . . . . . . . . . . . . . 12
1.7.4. Effort and flow variables . . . . . . . . . . . . . . . . . . . . . . . . . 13
1.7.5. Features and operating points of a system . . . . . . . . . . . . . . . 14
1.7.6. Generalized impedance . . . . . . . . . . . . . . . . . . . . . . . . . . 16
1.7.7. Determining the load effect. . . . . . . . . . . . . . . . . . . . . . . . 18
1.7.8. Measurement with a car battery . . . . . . . . . . . . . . . . . . . . . 19
1.7.9. Determining impedances . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.7.10. Generalized admittance . . . . . . . . . . . . . . . . . . . . . . . . . 20
1.8. Characteristics of an instrument. . . . . . . . . . . . . . . . . . . . . . . . 20
1.8.1. Components of static transfer functions. . . . . . . . . . . . . . . . . 21
1.8.2. Dynamic characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.8.3. Instrument performance . . . . . . . . . . . . . . . . . . . . . . . . . . 22
1.8.4. Combining transfer functions. . . . . . . . . . . . . . . . . . . . . . . 22
1.9. Implementing measurement acquisition. . . . . . . . . . . . . . . . . . . 23
1.9.1. Principles and methodology of measurement . . . . . . . . . . . . . 23
vi Fundamentals of Instrumentation and Measurement
1.9.2. Field measurement constraints: instrumentation on the road . . . . 26
1.10. Analyzing measurements obtained by an instrument. . . . . . . . . . . 26
1.10.1. Error reduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.10.2. Base definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
1.11. Partial conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1.12. Electronic instrumentation . . . . . . . . . . . . . . . . . . . . . . . . . . 28
1.13. Electronic instrumentation functionality. . . . . . . . . . . . . . . . . . 30
1.13.1. Programmable instrumentation. . . . . . . . . . . . . . . . . . . . . 32
1.13.2. Example of an electronic instrument: how a piezoelectric
sensor detects rattle in a combustion engine. . . . . . . . . . . . . . . . . . 33
1.14. The role of instrumentation in quality control. . . . . . . . . . . . . . . 34
1.15. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
1.16. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1.17. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 2. General Principles of Sensors . . . . . . . . . . . . . . . . . . . . . 41
François LEPOUTRE
2.1. General points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.1.1. Basic definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
2.1.2. Secondary definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2.2. Metrological characteristics of sensors. . . . . . . . . . . . . . . . . . . . 43
2.2.1. Systematic errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.2.2. Random uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.2.3. Analyzing random errors and uncertainties. . . . . . . . . . . . . . . 45
2.2.3.1. Evaluating random uncertainties. Standard deviations. Variances 45
2.2.3.2. Decisions about random uncertainties. . . . . . . . . . . . . . . . 47
2.2.3.3. Reliability, accuracy, precision. . . . . . . . . . . . . . . . . . . . 48
2.3. Sensor calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.3.1. Simple calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
2.3.2. Multiple calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.3.3. Linking international measurement systems . . . . . . . . . . . . . . 50
2.4. Band pass and response time . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.4.1. Harmonic response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2.4.2. Response time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.5. Passive sensor conditioners . . . . . . . . . . . . . . . . . . . . . . . . . . 59
2.5.1. The effect of polarization instabilities. . . . . . . . . . . . . . . . . . 59
2.5.2. Effects of influence variables. . . . . . . . . . . . . . . . . . . . . . . 61
2.5.3. Conditioners of complex impedance sensors. . . . . . . . . . . . . . 63
2.6. Conditioners for active sensors . . . . . . . . . . . . . . . . . . . . . . . . 64
2.6.1. Direct reading. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
2.6.2. Using operational amplifiers . . . . . . . . . . . . . . . . . . . . . . . 66
2.7. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Table of Contents vii
Chapter 3. Physical Principles of Optical, Thermal and
Mechanical Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
François LEPOUTRE
3.1. Optical sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
3.1.1. Energetic flux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
3.1.2. Luminous flux. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
3.1.3. The relative luminous efficiency curve V((cid:540)) of the human eye. . . 73
3.1.4. The black body: a reference for optical sensors . . . . . . . . . . . . 76
3.1.4.1. Black body radiation. . . . . . . . . . . . . . . . . . . . . . . . . . 77
3.1.4.2. Realization of black bodies . . . . . . . . . . . . . . . . . . . . . . 78
3.1.5. Radiation exchanges between a source and a detector . . . . . . . . 81
3.1.6. Definitions relating to optical sensors. . . . . . . . . . . . . . . . . . 82
3.1.6.1. Darkness currents. . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3.1.6.2. Spectral and total sensitivities . . . . . . . . . . . . . . . . . . . . 82
3.1.6.3. Sources of fundamental noise sources in optical sensors. . . . . 82
3.1.6.4. Specific detectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . 84
3.1.7. Semiconductors: the bases of optical sensors . . . . . . . . . . . . . 85
3.1.7.1. Molecular and crystalline bands . . . . . . . . . . . . . . . . . . . 85
3.1.7.2. Band structures in solids. . . . . . . . . . . . . . . . . . . . . . . . 87
3.1.8. Current expression in a material containing free charges . . . . . . 91
3.1.9. Photoconductor cells. . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
3.1.10. P-N junction and photodiodes. . . . . . . . . . . . . . . . . . . . . . 99
3.1.10.1. Non-polarized junctions . . . . . . . . . . . . . . . . . . . . . . . 99
3.1.10.2. P-N junction with direct bias . . . . . . . . . . . . . . . . . . . . 100
3.1.10.3. P-N junction in reverse bias. . . . . . . . . . . . . . . . . . . . . 101
3.1.10.4. Diode equation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
3.1.10.5. Illuminated P-N junctions . . . . . . . . . . . . . . . . . . . . . . 103
3.1.10.6. Principle of photodiode fabrication . . . . . . . . . . . . . . . . 103
3.1.10.7. Photodiode equation . . . . . . . . . . . . . . . . . . . . . . . . . 104
3.1.10.8. Electrical schema for a diode.. . . . . . . . . . . . . . . . . . . . 104
3.2. Force and deformation sensors . . . . . . . . . . . . . . . . . . . . . . . . 109
3.2.1. Resistive gauges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
3.2.2. Piezoelectric effect. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.2.2.1. Electrostriction, piezoelectricity and pyroelectricity . . . . . . . 111
3.2.2.2. The case of quartz . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
3.2.2.3. Constraint tensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
3.2.2.4. Other piezoelectric materials . . . . . . . . . . . . . . . . . . . . . 116
3.2.2.5. Construction of piezoelectric sensors . . . . . . . . . . . . . . . . 117
3.2.2.6. Using piezoelectric sensors. . . . . . . . . . . . . . . . . . . . . . 117
3.3. Thermal sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
3.3.1. Concepts related to temperature and thermometry . . . . . . . . . . 119
3.3.2. Thermodynamic temperature. . . . . . . . . . . . . . . . . . . . . . . 120
viii Fundamentals of Instrumentation and Measurement
3.3.3. Temperature scales currently in use and widely used
measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
3.3.4. Heat transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.3.4.1. Conduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
3.3.4.2. Convection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
3.3.4.3. Radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
3.3.4.4. Contact temperature measurement of solids . . . . . . . . . . . . 127
3.3.5. Contact thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
3.3.5.1. Resistive thermometers . . . . . . . . . . . . . . . . . . . . . . . . 128
3.3.5.2. The Seebeck effect. . . . . . . . . . . . . . . . . . . . . . . . . . . 129
3.3.5.3. The Peltier effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
3.3.5.4. The Thomson effect . . . . . . . . . . . . . . . . . . . . . . . . . . 131
3.3.5.5. The Seebeck electromotive force. . . . . . . . . . . . . . . . . . . 132
3.3.6. Features and uses of thermocouples. . . . . . . . . . . . . . . . . . . 134
3.4. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Chapter 4. Analog Processing Associated with Sensors. . . . . . . . . . . . . 137
Eduardo SANTANDER and Bernard JOURNET
4.1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
4.2. The problem of electronic noise. . . . . . . . . . . . . . . . . . . . . . . . 138
4.2.1. The origin of electronic noise. . . . . . . . . . . . . . . . . . . . . . . 138
4.2.2. Noise in an electronic chain. . . . . . . . . . . . . . . . . . . . . . . . 143
4.2.3. Signal-to-noise ratio . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
4.3. Amplifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4.3.1. Operational amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4.3.1.1. Feedback and counter-feedback in currents and tensions . . . . 148
4.3.1.2. Principle features of operational amplifiers . . . . . . . . . . . . 153
4.3.2. Instrumentation amplifiers . . . . . . . . . . . . . . . . . . . . . . . . 160
4.3.3. Isolation amplifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
4.3.4. Logarithmic amplifiers. . . . . . . . . . . . . . . . . . . . . . . . . . . 163
4.3.5. Multipliers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
4.4 Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165

Chapter 5. Analog Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
Paul BILDSTEIN
5.1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
5.2. Technological constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . 167
5.3. Methods of analog filter calculation . . . . . . . . . . . . . . . . . . . . . 169
5.3.1. Attenuation functions of standard low pass prototype filters . . . . 172
5.3.2. Transfer functions of common prototype low pass filters . . . . . . 174
5.3.3 Transfer functions of derived filters . . . . . . . . . . . . . . . . . . . 174
5.3.4. Filter synthesis carried out from the transfer function . . . . . . . . 175
Table of Contents ix
5.4. Passive filter using inductors and capacitors . . . . . . . . . . . . . . . . 177
5.4.1. Sensitivity; Orchard’s theorem and argument . . . . . . . . . . . . . 178
5.4.2. Low pass ladder filters. . . . . . . . . . . . . . . . . . . . . . . . . . . 179
5.4.2.1. Structures of basic low pass filters. . . . . . . . . . . . . . . . . . 180
5.4.2.2. The Darlington analytic synthesis . . . . . . . . . . . . . . . . . . 181
5.4.2.3. Examples of synthesis . . . . . . . . . . . . . . . . . . . . . . . . . 184
5.4.2.4. Direct digital synthesis. . . . . . . . . . . . . . . . . . . . . . . . . 187
5.4.3. L-C filters derived from a pass band. . . . . . . . . . . . . . . . . . . 189
5.4.4. Conversions of L-C filters; optimization . . . . . . . . . . . . . . . . 190
5.5. Active filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
5.5.1. Second order or biquadratic cells . . . . . . . . . . . . . . . . . . . . 192
5.5.2. Biquadratic cells with one operational amplifier . . . . . . . . . . . 192
5.5.3. Universal biquadratic cells with three or four amplifiers. . . . . . . 195
5.5.4. Elevated order active filters (elevated by putting biquadratic
cells in cascade). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199
5.5.5. Simulating an L-C filter. . . . . . . . . . . . . . . . . . . . . . . . . . 200
5.6. Switched capacitor filters. . . . . . . . . . . . . . . . . . . . . . . . . . . . 202
5.6.1. Integrators without sensitivity to stray capacitances . . . . . . . . . 205
5.6.2. Analysis of switched capacitor integrators . . . . . . . . . . . . . . . 206
5.6.3. Synthesis of switched capacitor filters . . . . . . . . . . . . . . . . . 207
5.6.4. Operational simulation of an L-C filter (leapfrog simulation). . . . 208
5.6.5. Switched capacitor biquadratic cells. . . . . . . . . . . . . . . . . . . 211
5.7. Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212

Chapter 6. Real-time Data Acquisition and Processing Systems . . . . . . . 215
Dominique MILLER
6.1. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
6.2. Electronic devices for signal sampling and quantification . . . . . . . . 216
6.2.1. Nyquist sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
6.2.2. Quantification noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
6.2.3. Over-sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219
6.2.3.1. Acquisition over-sampling . . . . . . . . . . . . . . . . . . . . . . 219
6.2.3.2. Over-sampling and reconstruction. . . . . . . . . . . . . . . . . . 222
6.2.4. Under-sampling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224
6.3. Analog-to-digital converters. . . . . . . . . . . . . . . . . . . . . . . . . . 229
6.3.1. Features of SINAD and ENOB converters. . . . . . . . . . . . . . . 230
6.3.2. (cid:520) - (cid:507) converters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
6.4. Real-time digital analysis by a specialized processor . . . . . . . . . . . 242
6.4.1. Fixed point and floating point analysis . . . . . . . . . . . . . . . . . 243
6.4.1.1. Fixed point notation . . . . . . . . . . . . . . . . . . . . . . . . . . 243
6.4.1.2. Floating point notation. . . . . . . . . . . . . . . . . . . . . . . . . 243
6.4.1.3. Comparison between the two notations. . . . . . . . . . . . . . . 245