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PID Controllers and Field Equipment Ratings
How are ranges of PID controllers decided with respect to field equipment rating?

How are ranges of PID controllers are decided with respect to field equipment rating?

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I suspect that others are as confused about your question as I am because there's no answer after a couple days.

What do you mean by the 'range' of a PID Controller? Its input is its input (considered 0-100% by the controller), its calculated output is 0-100% unless configured to some limited output range, say, 0-75%.

Are you talking about some other 'range'?

What rating are you referring to for field equipment? Hazardous area rating? Some other rating?

If the PID output is 4-20mA then presumably the positioner or final control element input is also 4-20mA, so one uses either an I/S barrier or conduit and seal-offs for Explosion proof.

The input is usually 4-20mA or 0-100%. 0% being 4mA and 100% bringing 20mA. The controller is tuned in its Proportional band, Integralrate, and Derivative Rate. The controller will calculate the output of 4-20 mA output to the final control element of valve. The IS barrier and cable seals have nothing to do with the controller.