tailieunhanh - Instrumentation for Process Measurement and Control, Third Editon

The perennially bestselling third edition of Norman A. Anderson's Instrumentation for Process Measurement and Control provides an outstanding and practical reference for both students and practitioners. It introduces the fields of process measurement and feedback control and bridges the gap between basic technology and more sophisticated systems. Keeping mathematics to a minimum, the material meets the needs of the instrumentation engineer or technician who must learn how equipment operates. I t covers pneumatic and electronic control systems, actuators and valves, control loop adjustment, combination control systems, and process computers and simulation. | l MlrXl Hrt Instrumentation for Process Measurement and Control Third Edition Norman A. Anderson THIRD EDITION Instrumentation for Process Measurement and Control NORMAN A. ANDERSON CHILTON COMPANY RADNOR PENNSYLVANIA CONTENTS Preface SECTION I FEEDBACK PROCESS CONTROL 1 1 Introduction to Process Control 1 Types of Processes 5 Processes with More Than One Capacity and Resistance 6 Dead Time 6 Measurement 7 Symbols 10 The Feedback Loop 10 Feedback Control 14 Controlling the Process 14 Selecting Controller Action 16 Upsets 17 Process Characteristics and Controllability 17 Controller Responses 18 On Off Control 19 Proportional Action 20 Integral Action Reset 23 Derivative Action 25 Selecting the Controller 27 Conclusion 29 Questions 30 2 Process Pressure Measuring Instruments 33 What Is Pressure 33 Units of Measurement 35 Pressure Measurement 35 The Pascal 36 Bar Versus Pascal 37 Gauge Absolute and Differential Pressure 37 Understanding the Effects of Gravity 38 Gravity-Dependent Units 38 Gravity-Independent Units 39 Pressure Standards 39 Plant Instruments That Measure Pressure Directly 44 .