Calibration

About the Author ix
Acknowledgements xi
Introduction xiii

Chapter 1 Calibration Principles 1
1.1 What Is Calibration? 1
1.2 What Are the Characteristics of a Calibration? 2
1.3 Why Is Calibration Required? 6
1.4 Who Performs Calibrations? – The Control System Technician 8
1.5 Characteristics of a Control System Technician 9
1.6 Loop Calibration vs Individual Instrument Calibration 10
1.7 Bench Calibration vs Field Calibration 11
1.8 Classification of Instruments 12
Chapter Summary 13
Review Questions 14

Chapter 2 Documentation 17
2.1 Calibration Procedure Content 19
2.2 Calibration Data Sheets (See Examples in Appendix A-4) 21
2.3 P&IDs (See Example in Appendix A-1) 23
2.4 Loop Diagrams (See Examples in Appendix A-2) 25
2.5 Instrument Specification Forms (See Examples in Appendix A-3) 26
2.6 Project Specifications 27
2.7 Manufacturer's Specifications 27
2.8 Calibration Intervals 28
2.9 Safety Considerations 29
2.10 Calibration Status Labels 30
Review Questions 31

Chapter 3 Temperature Instrument Calibration 33
3.1 What is Temperature? 33
3.2 Temperature Sensors 34
3.3 Signal Conversion 35
Review Questions 44

Chapter 4 Pressure Instrument Calibration 49
4.1 What is Pressure? 49
4.2 Challenges When Calibrating Pressure 50
4.3 Calibrating Pressure Gauges 52
4.4 Calibrating Pressure Transmitters 55
4.5 Calibrating Pressure Switches 55
Review Questions 56

Chapter 5 Level Instrument Calibration 61
5.1 Types of Level Instruments 61
5.2 Special Considerations with Level Calibration 64
5.3 Calibrating a Differential Pressure Level Transmitter 67
5.4 Calibrating a Capacitance Level Instrument 71
5.5 Calibrating an Ultrasonic Level Instrument 72
Review Questions 74

Chapter 6 Flow Instrument Calibration 77
6.1 Types of Flow Instruments 77
6.2 Calibration of Flowmeters 82
6.3 D/P Transmitter Calibration 83
6.4 Example: Magnetic Flowmeter Calibration 84
6.5 Flowmeter Calibration Using a Master Meter (Prover) 86
6.6 Gravimetric Method for Flowmeter Calibration (Measurement by Weight) 87
Review Questions 88

Chapter 7 Final Control Devices Calibration 89
7.1 Calibration of an I/P Transducer 95
7.2 Calibration of a Valve Positioner 96
7.3 Calibration of a Control Valve 97
Review Questions 97

Chapter 8 Process Analytical Instrument Calibration 101
8.1 pH Calibration Procedure 105
8.2 Diagnostic Test for pH Electrodes 106
8.3 Measuring Conductivity 107
8.4 Calibration Procedure with Explanations 109

Review Questions 111
Bibliography 113

Appendix A-1 Piping & Instrument Diagrams (P&IDs) 117
Appendix A-2 Loop Diagrams 119
Appendix A-3 Instrument Specifications 123
Appendix A-4 Calibration Procedures 145
Appendix A-5 Test Equipment 227
Appendix A-6 RTD and Thermocouple Tables 229
Appendix A-7 Conversion Tables 245
Appendix B Answers to Chapter Review Questions 249

Index 271