Mike: Nearly every analog instrument uses the 4-20 mA loop. Field transmitters, positioners, and variable frequency drives ...

PID loops are a central component of modulating boiler control systems with applications ranging from basic steam header pressure control to cascading 3-element drum level control. A modern ...

I was nursing a lukewarm vending machine coffee recently when I overheard two fresh-faced engineers complaining about the PID tuning process and coming up with ways to tear down centuries of control ...

The current-loop transmitter in the figure employs an unusual trick to inexpensively implement an optically isolated 4- to 20-mA transmitter: operation of the quad-channel LED/transistor ...