Essentials of Modern Measurements and Final Elements in the Process Industry: A Guide to Design, Configuration, Installation, and Maintenance
Advances in sensor technology and in digital positioner and variable speed drive algorithms, combined with smart features, offer a step change in the performance of modern measurement instruments and final elements. The installed accuracy of many smart instruments has increased by an order of magnitude. There has been a correspondingly dramatic reduction in the drift of transmitters and a similar improvement in the resolution of control valves.
This comprehensive resource aims to increase awareness of the opportunities afforded by modern measurement instruments and final elements, and to show how to get maximum benefit from the revolution in smart technologies. It builds an understanding of the fundamental aspects of measurements, measurement instruments, and final elements for applications in the process industry. The terminology and ideas presented provide a firm foundation for subsequent chapters that focus on what is needed for lowest life-cycle cost and best automation system performance. The last chapter provides a comprehensive exploration of the technology that supports the rapidly expanding opportunities of WirelessHART instrumentation.
No prior plant experience with industrial process instrumentation is required. For students and new employees, the chapters on fundamentals will improve productivity on the job and form a basis for further study. For the seasoned veteran, the book offers insights and serves as a guide through today's myriad automation products and application details. It provides a picture of the state of the art for 95% of the field instrumentation and final elements used, or under consideration, in a modern process plant. The reader is encouraged to seek further information on particular types of measurement instruments and final elements, which is available from manufacturers via the Internet and in instrumentation handbooks and ISA publications.
Table of Contents:
Preface xv
Chapter 1: Field Measurement Fundamentals 1
1-1. Learning Objectives 1
1-2. Introduction and Overview 2
1-3. Process Automation 21
1-4. Dynamics 43
1-5. Accuracy 49
1-6. Setup (Configuration) and Calibration 65
1-7. Installation 82
1-8. Questions 90
1-9. References 92
Chapter 2: Temperature Measurement 95
2-1. Learning Objectives 95
2-2. Introduction and Overview 95
2-3. Thermocouples and RTDs 106
2-4. Selection of a Temperature Sensor 113
2-5. Specifications 114
2-6. Setup and Calibration 116
2-7. Installation 116
2-8. Maintenance 126
2-9. Questions 127
2-10. References 127
Chapter 3: Pressure Measurement 129
3-1. Learning Objectives 129
3-2. Introduction and Overview 129
3-3. Principles 133
3-4. Selection 135
3-5. Specification 136
3-6. Setup and Calibration 140
3-7. Installation 141
3-8. Maintenance 142
3-9. Questions 145
3-10. References 145
Chapter 4: Flow Measurement 147
4-1. Learning Objectives 147
4-2. Introduction and Overview 147
4-3. Differential Pressure Flowmeters 161
4-4. Multivariable Differential Pressure Flowmeters 177
4-5. Vortex Flowmeters 189
4-6. Magnetic Flowmeters 198
4-7. Coriolis Mass Flowmeters 211
4-8. Questions 227
4-9. References 227
Chapter 5: Level Measurement 229
5-1. Learning Objectives 229
5-2. Introduction and Overview 229
5-3. Differential Pressure Level 237
5-4. Radar Level 248
5-5. Ultrasonic Level Measurement 268
5-6. Questions 273
5-7. References 273
Chapter 6: pH Measurement 275
6-1. Learning Objectives 275
6-2. Introduction and Overview 276
6-3. Principles 276
6-4. Selection 282
6-5. Specifications 297
6-6. Setup and Calibration 300
6-7. Installation 304
6-8. Maintenance 308
6-9. Questions 314
6-10. References 314
Chapter 7: Final Element Fundamentals 317
7-1. Learning Objectives 317
7-2. Introduction and Overview 317
7-3. Valves, Dampers, and Vanes 322
7-4. Variable Speed Drives 366
7-5. Dynamics 380
7-6. Linearity 401
7-7. Rangeability 416
7-8. Questions 419
7-9. References 420
Chapter 8: Control Valves 425
8-1. Learning Objectives 425
8-2. Introduction and Overview 425
8-3. Basic Construction and Operation 426
8-4. Sizing and Selection 434
8-5. Installation 449
8-6. Adjustments 453
8-7. Maintenance 455
8-8. Diagnostics 461
8-9. Valve and Actuator Capabilities 466
8-10. Questions 483
8-11. References 484
Chapter 9: Wireless 487
9-1. Learning Objectives 487
9-2. Introduction and Overview 487
9-3. Principles 496
9-4. Security and Reliability 501
9-5. Communication Rules 503
9-6. Process Control 520
9-7. Installation of a Wireless Network 531
9-8. Questions 534
9-9. References 535
Appendix A: Answers to Chapter Questions 537
Appendix B: Top Ten Things to Consider Before Selecting Your VFD 553
Appendix C: Effect of Sample Time on Process Control 555
Index 561
