Which device is an example of a Final Control Element?

• A. Valves
• B. Thermocouples
• C. Transmitters
• D. Analyzers

Answer: (A)

A Final Control Element is the device that directly implements the controller’s output to affect the process variable. It sits at the end of the control loop and turns a command into a physical action. Valves fit this role because the controller’s signal positions the valve to modulate flow, pressure, or temperature, directly changing the process.

The other devices are sensing or measurement tools: a thermocouple measures temperature and converts it to a signal; a transmitter sends that signal to the controller; an analyzer examines a sample to determine composition or quality. They provide information but don’t enact the change in the process themselves.