Linear position sensors: theory and application

LINEAR POSITION SENSORS......Page 4
CONTENTS......Page 10
PREFACE......Page 14
1.1 Is It a Sensor or a Transducer?......Page 16
1.2 Position versus Displacement......Page 18
1.4 Contact or Contactless Sensing and Actuation......Page 20
1.6 Application versus Sensor Technology......Page 23
2.2 Measuring Range......Page 25
2.3 Zero and Span......Page 26
2.4 Repeatability......Page 27
2.5 Nonlinearity......Page 28
2.6 Hysteresis......Page 34
2.7 Calibrated Accuracy......Page 36
2.9 What Does All This about Accuracy Mean to Me?......Page 38
2.10 Temperature Effects......Page 40
2.11 Response Time......Page 41
2.12 Output Types......Page 43
2.13 Shock and Vibration......Page 47
2.14 EMI/EMC......Page 49
2.15 Power Requirements......Page 52
2.16 Intrinsic Safety, Explosion Proofing, and Purging......Page 53
2.17 Reliability......Page 60
3.1 Resistive Position Transducers......Page 62
3.2 Resistance......Page 63
3.4 Linear Position Transducer Design......Page 64
3.5 Resistive Element......Page 67
3.6 Wiper......Page 69
3.8 Signal Conditioning......Page 70
3.10 Performance Specifications......Page 72
3.11 Typical Performance Specifications and Applications......Page 75
4.1 Capacitive Position Transducers......Page 77
4.2 Capacitance......Page 78
4.3 Dielectric Constant......Page 80
4.4 History of Capacitive Sensors......Page 81
4.5 Capacitive Position Transducer Design......Page 82
4.6 Electronic Circuits for Capacitive Transducers......Page 85
4.7 Guard Electrodes......Page 89
4.8 EMI/RFI......Page 90
4.9 Typical Performance Specifications and Applications......Page 91
5.1 Inductive Position Transducers......Page 93
5.2 Inductance......Page 94
5.3 Permeability......Page 98
5.4 History of Inductive Sensors......Page 99
5.5 Inductive Position Transducer Design......Page 100
5.6 Coil......Page 101
5.8 Signal Conditioning......Page 104
5.10 Typical Performance Specifications and Applications......Page 107
6.1 LVDT Position Transducers......Page 109
6.3 LVDT Position Transducer Design......Page 110
6.4 Coils......Page 112
6.5 Core......Page 113
6.6 Carrier Frequency......Page 115
6.7 Demodulation......Page 116
6.8 Signal Conditioning......Page 119
6.9 Advantages......Page 121
6.10 Typical Performance Specifications and Applications......Page 123
7.1 Hall Effect Transducers......Page 124
7.2 The Hall Effect......Page 125
7.3 History of the Hall Effect......Page 127
7.4 Hall Effect Position Transducer Design......Page 128
7.5 Hall Effect Element......Page 130
7.6 Electronics......Page 131
7.7 Linear Arrays......Page 133
7.8 Advantages......Page 134
7.9 Typical Performance Specifications and Applications......Page 135
8.1 Magnetoresistive Transducers......Page 137
8.2 Magnetoresistance......Page 138
8.3 History of Magnetoresistive Sensors......Page 144
8.4 Magnetoresistive Position Transducer Design......Page 145
8.6 Linear Arrays......Page 146
8.7 Electronics......Page 148
8.9 Typical Performance Specifications and Applications......Page 149
9.1 Magnetostrictive Transducers......Page 151
9.2 Magnetostriction......Page 152
9.3 History of Magnetostrictive Sensors......Page 154
9.5 Waveguide......Page 155
9.6 Position Magnet......Page 157
9.7 Pickup Devices......Page 159
9.9 Electronics......Page 160
9.10 Advantages......Page 162
9.11 Typical Performance Specifications......Page 163
9.12 Application......Page 164
10.2 History of Encoders......Page 166
10.3 Construction......Page 167
10.4 Absolute versus Incremental Encoders......Page 168
10.5 Optical Encoders......Page 169
10.6 Magnetic Encoders......Page 170
10.7 Quadrature......Page 171
10.8 Binary versus Gray Code......Page 172
10.9 Electronics......Page 173
10.10 Advantages......Page 174
10.11 Typical Performance Specification and Applications......Page 175
REFERENCES......Page 177
INDEX......Page 180