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Today's automation industry quiz question comes from the ISA Certified Automation Professional certification program. ISA CAP certification provides a non-biased, third-party, objective assessment and confirmation of an automation professional's skills. The CAP exam is focused on direction, definition, design, development/application, deployment, documentation, and support of systems, software, and equipment used in control systems, manufacturing information systems, systems integration, and operational consulting. Click this link for more information about the CAP program. The following question comes from the CAP study guide, Performance Domain III, System Design − design, specify, and procure the hardware/software used in the system

How is PID defined in the phrase "PID control loop"?

a) Proportional Instrument Device
b) Piping Instrumentation Diagram
c) Percentage Integration Delta
d) Proportional Integral Derivative
e) none of the above

The PID term as described refers to the loop control technique used in controllers.

Proportional Integral Derivative is the correct term as referenced. A PID control loop includes proportional, integral, and derivative functions to control the process.

The correct answer is D, Proportional Integral Derivative.