Which term best describes a collection of control devices and other components necessary for automatic control of a process or subprocess?

Which term best describes a collection of control devices and other components necessary for automatic control of a process or subprocess?

• A. Control panel
• B. Process map
• C. Operator interface
• D. Control loop

Answer: (D)

A control loop is the arrangement of sensors, controllers, and actuators that keeps a process operating automatically by using feedback. The sensor measures the process variable, the controller compares that measurement to the desired setpoint, and the actuator adjusts the process input to reduce any difference. This closed feedback path continuously corrects deviations, like a thermostat adjusting heating to maintain the target temperature.

That makes it the best description for a collection of control devices and components required for automatic control. The other terms refer to different ideas: a control panel is the hardware you interact with manually, an operator interface is the human-machine interface, and a process map is a diagram of the steps in a process, not the automatic control chain.