# AutoQuiz: What is the Integral Action, Which is Part of a PID Algorithm, Often Called?

AutoQuiz is edited by Joel Don, ISA’s social media community manager.

Today’s automation industry quiz question comes from the ISA Certified Control Systems Technician (CCST) program. Certified Control System Technicians calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables. This question is from the Level I study guide, Domain 4, start-up. Level I represents a professional who has a five-year total of education, training, and/or experience.

The integral action, which is part of a PID algorithm, is often called:

A) rate
B) reset
C) gain
D) insert
E) none of the above

The three terms (proportional-integral-derivative) of the PID algorithm have other designations. Rate (answer A) action is another name for derivative control mode, and reset (answer B) is another name for integral control action.

The proportional term relates to the gain (answer C) in that the term gain, proportional is the ratio of the change in output caused by the proportional control action to the change in input. Answer D has no relationship to PID control.

Here is the PID algorithm:

Where:
G = gain
R = reset (repeats per minute)
D = derivative (minutes)

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