Proportional-integral-derivative control methods — more commonly known as PID control — have been used in industrial applications for as long as anybody can remember.Proportional-integral-derivative control methods — more commonly known as PID control — have been used in industrial applications for as long as anybody can remember. Over the decades, control engineers have developed tuning techniques to get loops to behave as desired. Dozens — if not hundreds — of ways exist to determine the “magic settings” to get a loop to remain stable while quickly responding to process upsets and setpoint changes.
Industrial process temperature control loops offer some unique challenges. When a control engineer wants to tune a flow or pressure loop, the control device can be adjusted with an infinite number of steps, for all practical purposes. A valve usually can be tweaked just the right amount to make the process variable hug the setpoint.