You ever used Eurotherm's 818 loop controllers? I've used them in semiconductor applications where I needed temperature control of 0.1degC resolution.Yokogawa's "green" series are a nice cheap loop controller as well. They're not as accurate as Eurotherm's but are very cheap and easy to interface them with your PLC or control PC.
Kurt9,No. As I recall though most temp. controllers are based on the Gain/Time factors the chemical folks use.
Yes, they are. Nonetheless, they work quite well once they are properly tuned.
Kurt. I think that was my point. That Gain/Time tuning is more physical. When I dis my original work on auto-tuning I looked at a number of temp. controllers in order to get a handle on the algorithms they used. Not much help.What I found the most useful was a book on control theory from one of the engineering societies which had a number of fundamental papers including Ziegler-Nichols and some of the initial papers on "shock" tuning. I wish I could remember which society. Might have been the Society Of Chemical Engineers.
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