32.4 High-reliability control systems
As discussed at the beginning of this chapter, instrumentation safety may be broadly divided into two categories: the...
Category: General
32.3 Practical measures of reliability
In reliability engineering, it is important to be able to quantity the reliability (or conversely, the probability of...
32.2 Concepts and laws of probability
While the term “probability” may evoke images of imprecision, probability is in fact an exact mathematical...
Chapter 32 Industrial Process Safety and Instrumentation
This chapter discusses instrumentation issues related to industrial process safety. Instrumentation safety may be...
31.8 Techniques for analyzing control strategies
Control strategies such as cascade, ratio, feedforward, and those containing limit and selector functions can be quite...
31.7 Limit, Selector, and Override controls
Another category of control strategies involves the use of signal relays or function blocks with the ability to switch...
31.6 Feedforward with dynamic compensation
As we have seen, feedforward control is a way to improve the stability of a feedback control system in the face of...
31.5 Feedforward control
“Feedforward” is a rather under-used control strategy capable of managing a great many types of process problems....
31.4 Relation control
A control strategy similar to ratio control is relation control. This is similar to ratio control in that a...
31.3 Ratio control
Most people reading this book have likely had the experience of adjusting water temperature using two hand valves as...
31.2 Cascade control
A simple control system drawn in block diagram form looks like this: Information from the measuring device...
Chapter 31 Basic Process Control Strategies and Control System Configurations
In a simple control system, a process variable (PV) is measured and compared with a setpoint value (SP). A manipulated...
30.6 Tuning PID Controllers
Learning how to tune PID controllers is a skill born of much practice. Regardless of how thoroughly you may study the...
30.5 A Comparison of PID Controller Tuning Techniques
In this section I will show screenshots from a process loop simulation program illustrating the effectiveness of...
30.4 Heuristic PID Tuning Procedures
In contrast to quantitative tuning procedures where definite numerical values for P, I, and D controller settings are...
