Instrumentation for Process Measurement and Control, Third Editon

by Anderson; Norman A.

• ISBN13: 9780849398711
• ISBN10: 0849398711
• eBook ISBN(s): 9781351438100
• Edition: 3rd
• Format: Hardcover
• Copyright: 1997-10-22
• Publisher: CRC Press

Summary

This best-selling third edition of Norman A. Anderson's Instrumentation for Process Measurement and Control, Third Edition contains updated material on new equipment and probes further into topics introduced in previous editions. The book introduces the fields of process measurement and feedback control, and bridges the gap between basic technology and more sophisticated systems that offer promise for the future.

Table of Contents

Preface
SECTION I FEEDBACK PROCESS CONTROL	1	(178)
Introduction to Process Control	1	(32)
Types of Processes	5	(1)
Processes with More Than One Capacity and Resistance	6	(1)
Dead Time	6	(1)
Measurement	7	(3)
Symbols	10	(1)
The Feedback Loop	10	(4)
Feedback Control	14	(1)
Controlling the Process	14	(2)
Selecting Controller Action	16	(1)
Upsets	17	(1)
Process Characteristics and Controllability	17	(1)
Controller Responses	18	(1)
On/Off Control	19	(1)
Proportional Action	20	(3)
Integral Action (Reset)	23	(2)
Derivative Action	25	(2)
Selecting the Controller	27	(2)
Conclusion	29	(1)
Questions	30	(3)
Process/Pressure Measuring Instruments	33	(36)
What Is Pressure?	33	(2)
Units of Measurement	35	(1)
Pressure Measurement	35	(1)
The Pascal	36	(1)
Bar Versus Pascal	37	(1)
Gauge, Absolute, and Differential Pressure	37	(1)
Understanding the Effects of Gravity	38	(1)
Gravity-Dependent Units	38	(1)
Gravity-Independent Units	39	(1)
Pressure Standards	39	(5)
Plant Instruments That Meassure Pressure Directly	44	(1)
Bell Instrument	44	(1)
Slack or Limp-Diaphragm	44	(2)
Pressure Gauges	46	(2)
Liquid or Steam Pressure Measurement	48	(1)
Seals and Purges	48	(1)
Pulsation Dampener	48	(1)
Metallic Bellows	49	(3)
Pressure Transmitters	52	(1)
Signal Transmissions	52	(1)
Pneumatic Recorders and Indicators	53	(2)
Mechanical Pressure Seals	55	(4)
Calibration Techniques	59	(1)
Field Standard	59	(1)
Portable Pneumatic Calibrator	59	(1)
Force-Balance Pneumatic Pressure Transmitter	60	(2)
Pneumatic Relay	62	(1)
Principle of Operation	63	(1)
Absolute Pressure Transmitter	64	(1)
Questions	65	(4)
Level and Density Measurements	69	(21)
Level Measurement Methods	69	(1)
Float-and-Cable	70	(1)
Displacement (Buoyancy)	71	(2)
Head or Pressure	73	(5)
Capacitance	78	(1)
Conductance	79	(1)
Radiation	79	(1)
Weight	79	(1)
Ultrasonic	80	(1)
Thermal	81	(1)
Density Measurement Methods for Liquids and Liquid Slurries	81	(1)
Hydrostatic Head	82	(2)
Radiation	84	(1)
Vibration	84	(1)
Temperature Effects and Considerations	84	(1)
Differential Pressure Transmitter	85	(2)
Questions	87	(3)
Flow Measorement	90	(36)
Constriction or Differential Head Type	91	(3)
Primary Devices	94	(5)
Secondary Devices	99	(1)
Relating Flow Rate to Differential	100	(3)
Effect of Temperature on Flow Rate	103	(6)
Variable Area Meters (Rotameter)	109	(1)
Open-Channel Flow Rate Measurements	109	(1)
Primary Devices	110	(6)
Installation and Selection Considerations	116	(1)
Velocity Flowmeters	117	(1)
Magnetic Flowmeter	117	(4)
Vortex Flowmeter	121	(1)
Turbine Flowmeter	122	(1)
Other Flowmeters	123	(1)
Conclusion	124	(1)
Questions	124	(2)
Temperature and Humidity Measurements	126	(25)
Temperature	126	(2)
Filled Thermal Systems	128	(2)
Electrical Systems	130	(1)
Thermocouples	130	(9)
Resistance Thermal Detectors	139	(5)
Thermistors	144	(1)
Humidity Measurements	144	(4)
Questions	148	(3)
Analytical Measurements	151	(28)
Electrical Conductivity	151	(3)
Types of Calibration	154	(1)
Calibration in Conductivity	154	(1)
Calibration in Terms of Concentration of Electrolyte	155	(1)
Polarization	156	(1)
Cell Construction	156	(1)
Electrodeless Conductivity Measurements	157	(2)
Hydrogen Ion Activity (pH)	159	(1)
Ionization or Dissociation	159	(2)
The pH Scale	161	(3)
Measurement of pH---The Glass Electrode	164	(1)
Reference Electrode	165	(3)
Temperature Compensation	168	(1)
Reading the Output of the pH Electrodes	169	(1)
pH Control	170	(2)
Summary	172	(1)
Oxidation-Reduction Potential	172	(1)
Ion-Selective Measurement	173	(1)
Chromatography	174	(1)
Capacitance	175	(1)
References	176	(1)
Questions	176	(3)
SECTION II PNEUMATIC AND ELECTRONIC CONTROL SYSTEMS	179	(80)
The Feedback Control Loop	179	(26)
The Closed-Loop Control System	183	(1)
Phase Shift Through RC Networks	184	(1)
Oscillation	184	(3)
Stability in the Closed-Loop System	187	(1)
Nonlinearities	188	(1)
Controllers and Control Modes	189	(1)
Two-Position Control	189	(2)
Throttling Control	191	(2)
Application of Proportional Control	193	(2)
Proportional-Plus-Integral Control	195	(4)
Adding Derivative (Rate)	199	(1)
Selecting the Controller	200	(2)
Questions	202	(3)
Pneumatic Control Mechanisms	205	(32)
The Flapper-Nozzle Unit	205	(2)
Valve Relay or Pneumatic Amplifier	207	(1)
The Linear Aspirating Relay or Pneumatic Amplifier	208	(1)
Proportional Action	209	(2)
Control Mechanism Requirements	211	(1)
The Automatic Controller	212	(3)
Derivative and Integral	215	(1)
Manual Control Unit	216	(1)
Transfer	217	(3)
Set Point	220	(3)
The Closed-Loop Pneumatic Control System	223	(2)
The Process	225	(1)
The Controller Set Point	225	(1)
Valve and Actuator	226	(1)
Final Control Element	227	(1)
Dynamic Behavior of Closed-Loop Control Systems	228	(2)
Adjusting the Controller	230	(1)
Batch Controller	231	(1)
Principle of Operation	232	(1)
Load Bias (Preload)	233	(1)
Questions	234	(3)
Electronic (Analog) Control Systems	237	(22)
Feedwater Control Systems	238	(1)
Transmetters	238	(3)
The Controllers	241	(2)
Principle of Operation	243	(1)
Increase/Decrease Switch	244	(1)
Deviation Signal Generation	244	(1)
Derivative Action	244	(1)
Proportional Band Action	245	(1)
Final Summing and Switching	245	(1)
High and Low Limits	245	(1)
External Integral ( -- R) Option	246	(1)
External Summing ( -- S) Option	246	(1)
Power Supply Fault Protection Circuit	246	(1)
Automatic/Manual Switch	247	(1)
Controller Adjustments	247	(1)
General Description of the Feedwater Control System	247	(1)
Control Station	248	(1)
M/2AX + A4-R Drum Level Control Unit	249	(1)
M/2AX + A4 Feedwater Control Unit	250	(1)
M/2AP + SUM Feedwater/Steam Flow Computing Unit	250	(1)
Square Root Extractor	250	(2)
Feedwater Control	252	(1)
Closed-Loop Operation	252	(2)
Comparison of Electronic and Pneumatic Systems	254	(2)
Questions	256	(3)
SECTION III ACTUATORS AND VALVES	259	(36)
Actuators	259	(11)
Valve Actuator	259	(2)
Valve Positioner	261	(2)
Electrical Signals	263	(2)
Principle of Operation	265	(2)
Electric Motor Actuators	267	(1)
Questions	268	(2)
Control Valves	270	(25)
Capacity of a Control Valve	272	(1)
Valve Sizing	272	(1)
Determining Pressure Drop Across the Valve	273	(1)
Cavitation and Flashing	274	(2)
Valve Rangeability	276	(2)
Selection Factors	278	(1)
Sequencing-Control Valves	279	(2)
Viscosity Corrections	281	(11)
References	292	(1)
Questions	292	(3)
SECTION IV CONTROL LOOP ADJUSTMENT AND ANALYSIS	295	(48)
Controller Adjustments	295	(9)
Proportional-Only Controller	295	(1)
Proportional-Plus-Integral Controller	296	(1)
Adding Derivative Action	297	(1)
Tunning Maps	298	(1)
Adjusting a Controller with the Proportional, Integral, and Derivative Mode	299	(2)
Closed-Loop Cycling Method	301	(2)
Questions	303	(1)
Step-Analysis Method of Finding Time Constant	304	(24)
Block Diagram	304	(4)
Step Analysis of Single-Time-Constant System	308	(1)
Step Analysis of Two-Time-Constant System	309	(1)
Percent-Incomplete Method	310	(3)
Multicapacity System	313	(2)
Finding Control Modes by Step Analysis	315	(1)
On/Off Control Action	316	(1)
Proportional Control Action	316	(2)
Proportional-Plus-Integral Action	318	(1)
Proportional-Plus-Derivative Control Action	319	(1)
Proportional-Plus-Derivative-Plus-Integral Control Action	320	(1)
Using the Reaction Curve to Determine Controller Adjustments	320	(4)
References	324	(1)
Questions	325	(3)
Frequency Response Analysis	328	(15)
Finding the Time Constant from the Bode Diagram	331	(1)
Testing a System	331	(4)
Control Objectives	335	(1)
Adding Derivative	336	(1)
Adding Integral	337	(2)
Adjusting the Proportional Band	339	(1)
Closed-Loop Response	339	(1)
Conclusion	340	(1)
Questions	341	(2)
SECTION V COMBINATION CONTROL SYSTEMS	343	(29)
Split-Range, Auto-Selector, Ratio, and Cascade Systems	343	(17)
Duplex or Split-Range Control	343	(2)
Auto-Selector or Cutback Control	345	(3)
Nonpipeline Application of Auto-Select/Cutback Control Systems	348	(4)
Cascade Controller	352	(3)
Saturation in Cascaded Loops	355	(2)
Questions	357	(3)
Feedforward Control	360	(12)
Definition	360	(1)
History	360	(1)
Advantages	360	(1)
Technique	361	(1)
Application to Heat Exchanger	361	(8)
Distillation Control	369	(1)
Conclusion	370	(1)
References	370	(1)
Questions	371	(1)
SECTION VI PROCESS COMPUTERS AND SIMULATION	372	(64)
Computer Interface and Hardware	372	(16)
Basic Elements of the Computer	372	(1)
Input	373	(1)
Central Processing Unit (CPU)	373	(1)
Output	374	(1)
Types of Memory	374	(1)
Core	374	(1)
Drum	375	(1)
Disk	375	(1)
Semiconductor (Solid-State)	376	(1)
Operator Communication Devices	377	(1)
Process Interface Equipment	377	(8)
Conclusion	385	(1)
Questions	385	(3)
Computer Software and Operation	388	(14)
A Brief Introduction	388	(2)
Basic Computer Operation	390	(4)
Real-Time Clock and Power Fail/Restart Logic	394	(1)
Control Software	394	(2)
Achieving Process Control	396	(4)
Questions	400	(2)
Programmed Control Systems	402	(11)
Description of Circuit	403	(2)
Sequential Control Systems	405	(1)
Programmable Controllers	406	(1)
Programming Language	406	(2)
Programming	408	(1)
Logic System Automation	409	(1)
System Control Displays	410	(1)
Conclusion	411	(1)
Questions	411	(2)
Constructing and Instrumenting Real and Simulated Processes	413	(23)
Simulated Processes	413	(1)
Constructing an Electric Process Simulator	414	(1)
The Foxboro Electronic Process Simulator	415	(5)
Pneumatic Process Simulator	420	(3)
Operation of the Pneumatic Simulator	423	(1)
Time Base	424	(3)
Real Processes	427	(6)
Questions	433	(3)
Appendix	436	(44)
Units and Conversion Tables for Process Control	436	(15)
Specific Gravities of Common Liquids	451	(1)
Standard Pipe Dimensions	452	(1)
Properties of Saturated Steam and Saturated Water	453	(1)
Resistance Values	454	(1)
Velocity and Pressure Drop	455	(3)
Thermocouple Temperature	458	(18)
Realative Humidity (% saturation) Tables	476	(4)
Glossary	480	(8)
Answers to Questions	488	(3)
Bibliography	491	(1)
Index	492