Industrial Process Sensors

✍ Scribed by David M. Scott

• Publisher: CRC Press
• Year: 2007
• Tongue: English
• Leaves: 240
• Category: Library

✦ Synopsis

As manufacturing processes become increasingly complex, industry must rely on advanced sensor technology and process control to improve efficiency and product quality. Processes now need a variety of on-line measurements, such as film thickness, particle size, solids concentrations, and contamination detection. Industrial Process Sensors provides a coherent review of the physical principles, design, and implementation of a wide variety of in-process sensors used to control manufacturing operations. Real data from commercial installations illustrates the operation and limitations of these devices.

The book begins with a review of the basic physics of sound, light, electricity, and radiation, with a focus on their role in sensor devices. The author introduces the generic sensor model and discusses the propagation of measurement errors. He goes on to describe conventional process sensors that measure temperature, pressure, level, and flow. The second half of the book focuses on more advanced topics, such as particle size measurement in slurries and emulsions, tomography and process imaging of manufacturing operations, on-line measurement of film thickness, identification of polymer type for recycling, and characterization of reinforced polymers and composites.

By exploring both theory and final implementation of sensors used to control industrial manufacturing processes, Industrial Process Sensors provides the information you need to develop solutions to a wide range of industrial measurement needs.

✦ Table of Contents

Industrial Process Sensors......Page 1
Contents......Page 5
Preface......Page 9
Acknowledgments......Page 10
About the Author......Page 11
1.1 Motivation for Process Measurement......Page 12
1.2 Process Sensors......Page 13
1.3 The Physics of Measurement......Page 15
2.1 The Sensor Model......Page 18
2.2 Units of Measure......Page 19
2.3 Simple Statistics......Page 20
2.4 Sources of Error......Page 22
2.5 Analysis of Error......Page 24
Suggested Reading......Page 26
3.1 Sound......Page 27
3.2 Waves......Page 29
3.3 The Wave Equation and Its Solutions......Page 31
3.4.2 Refraction......Page 33
3.4.3 Superposition and Interference......Page 35
3.4.5 Doppler Shift......Page 37
3.4.6 Diffraction......Page 39
3.5 Sound Generation and Detection......Page 40
3.6 Appendix on the Wave Equation......Page 41
Suggested Reading......Page 43
4.1 Electromagnetic Waves......Page 44
4.2.1 Mirrors......Page 47
4.2.3 Beam Splitters......Page 48
4.2.4 Lenses......Page 49
4.2.6 Filters......Page 50
4.2.7 Modulators......Page 51
4.3.1 Incoherent Sources......Page 53
4.3.2 Lasers......Page 54
4.3.3 Detectors......Page 55
Suggested Reading......Page 57
5.1.1 Potential and Current......Page 58
5.1.2 Resistance......Page 63
5.1.3 Capacitance and Inductance......Page 64
5.2.1 Diodes......Page 67
5.2.2 Transistors......Page 68
5.3 Amplifiers......Page 69
5.4 Digitization......Page 72
Suggested Reading......Page 74
6.1 Introduction......Page 76
6.2.1 Energetic Electromagnetic Waves......Page 78
6.2.2 Energetic Particles......Page 79
6.3.1 Nuclear Decay......Page 80
6.3.2 X-Ray Generators......Page 81
6.4.1 Counters......Page 82
6.4.2 Imaging Devices......Page 83
6.5 Safety Considerations......Page 86
Suggested Reading......Page 87
7.2 Temperature Sensors......Page 88
7.2.1 Thermistors......Page 89
7.2.2 Thermocouples......Page 91
7.2.3 Infrared Thermometers......Page 92
7.3.1 Diaphragms......Page 94
7.4 Level Sensors......Page 96
7.4.2 Ultrasonic and Acoustic Sensors......Page 97
7.5.1 Heat Transfer Sensors......Page 98
7.5.2 Ultrasonic Sensors......Page 99
7.5.3 Electromagnetic Sensors......Page 102
7.5.4 Differential Pressure Sensors......Page 103
Suggested Reading......Page 104
8.1.1 Representation of Particle Size......Page 106
8.1.2 Types of PSD Instruments......Page 110
8.2.2 Optical Counting......Page 111
8.2.3 The Normalization of Counting Data......Page 113
8.2.4 Focused Back-Reflection Method......Page 116
8.3.1 Static Light Scattering......Page 117
8.3.2 Dynamic Light Scattering......Page 120
8.4 Ultrasonic Attenuation Spectroscopy......Page 122
8.4.1 Theoretical Background......Page 123
8.4.2 Hardware Considerations......Page 128
8.4.3 A Practical Ultrasonic Spectrometer......Page 130
Validation of the ECAH Model......Page 135
Validation of the Inverse Algorithm......Page 136
Monitoring and Control of Milling......Page 137
Precipitation......Page 141
8.5 Appendix on Recovery of the PSD......Page 144
Suggested Reading......Page 148
9.1 Introduction......Page 150
9.2 Direct Imaging......Page 151
9.3 Tomographic Imaging......Page 152
9.4 Case Study: Crystallization......Page 156
9.5 Case Study: Granulation......Page 158
9.6 Case Study: Media Milling......Page 163
Suggested Reading......Page 167
10.1 Radiation Gauges......Page 168
10.2 Ultrasonic Thickness Gauging of Ultrathin Films......Page 169
10.2.1 Theory of Measurement......Page 170
10.2.3 Effect of Ambient Conditions......Page 172
Pressure Dependence......Page 174
Humidity Dependence......Page 175
Radiation Pattern......Page 177
X-Y Sensitivity......Page 179
Effective Spot Size......Page 182
Frequency Response......Page 185
10.2.5 Summary......Page 186
10.3 Optical Thickness Measurements for Single and Multilayer Films......Page 187
10.3.1 Principle of Operation......Page 188
10.3.2 The Optical Sensor and Test Block......Page 189
10.3.3 Single Film Thickness Measurements......Page 191
10.3.4 Application to Multilayer Films......Page 193
10.4 Appendix on the Thin-Plate Approximation......Page 194
10.5.1 Laser Beams and Gaussian Optics......Page 199
10.5.3 Depth of Focus......Page 201
10.6 Appendix on Thickness Correction......Page 202
10.6.1 Single-Ply Films......Page 203
10.6.2 Multi-Ply Laminates......Page 204
Suggested Reading......Page 206
11.1 Identification of Polymer Type......Page 208
11.1.1 NIR Absorbance Spectra......Page 209
11.1.2 Neural Networks......Page 211
11.1.3 Hardware Implementation......Page 212
11.2 Contamination Detection in Molten Polymer......Page 214
11.3.1 Applications of Reinforced Polymers......Page 216
11.3.2 Measurement Principles......Page 218
11.3.3 Hardware Implementation......Page 220
11.3.4 Experimental Results......Page 221
11.4 Measurement of Part Dimensions Using Radioscopy......Page 223
11.4.1 Concept......Page 224
11.4.3 Depth-of-Flaw Measurements......Page 225
11.4.4 Wall Thickness Measurements......Page 227
11.5 Appendix on the Calculation of Loading......Page 228
Notes......Page 231
References......Page 234