The amount of information that the generalist needs to know is staggering. The knowledge needed is buried in a hundred thousand pages of publications and presentations that are oriented toward the specialist. Here I provide the essentials for the best field instrumentation system.
A lot of time and money can be spent deciding which valves need positioners and which flows need measurement. We tend to look at short term costs such as hardware and not the cost of troubleshooting and the implications as to plant performance.
A flowmeter that is not measuring properly can cause many problems. In a custody-transfer application involving rude oil or natural gas, even the smallest error can cost a customer millions of dollars a year.
We continue this series with the steps for designing control strategies. Simple rules of thumb will be offered for setting up cascade, composition, flow, level, pH, pressure, and temperature control systems. Examples of common unit operations will help provide understanding of the steps involved.