I am often astounded by finding really basic problems with controls in plants, which have operated that way for years. These problems are so basic that one can only wonder at how these controls could ...
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Answer to the question at the end of Case History 166 (www.instrumentation.co.za/8690r) In the last Case History article, I suggested you try and see what was not so good about a level control, which ...
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Control loop expert Michael Brown recently received a question from reader, Hansell Williams. The question relates to applying neural network and machine learning concepts to plant automation and control. ...
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I was present at a very interesting discussion the other day with people who are leaders in the automation and control industry. The subject was how jobs would disappear over the next decade or two as ...
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I have published many articles showing problems in control loops with figures showing the tests conducted to determine the problems. This time, by way of a change, I would like to suggest that readers ...
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I often publish articles showing valve problems. One of the reasons is that I do not think many people understand that valves are generally responsible for 75-80% of all control loop problems. When it ...
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I was recently asked to conduct a control loop audit on a mineral extraction processing plant which was fairly old and had been acquired by new owners. A new and very modern control system had been installed ...
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I have often written about the huge advantages of using cascade control on processes with very slow dynamics. It is particularly useful when it comes to most temperature related processes, which are normally ...
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Eliakim Musikiti read one of my articles in SA Instrumentation and Control and emailed me to ask what the differences are between PLCs and DCSs. I started replying to him and then thought that it would ...
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In a recent assignment to sort out problems being experienced in a petrochemical refinery, I came across the following two examples:       Drum pressure misbehaving The first was with the control of an ...
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It still fascinates me that so many control problems are caused by poor operation of control valves. I have encountered and recorded hundreds of cases of such problems. What is amazing is that many plant ...
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I was recently asked to help with a client who treats a product in an autoclave and was complaining that they always got overshoot on a step setpoint change to holding temperature. The following is taken ...
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