Red Seal Instrumentation and Control Technician Practice Exam

In a control system, which component directly implements actions based on signals received?

1. Transmitter

2. Sensor

3. Actuator

4. Controller

The correct answer is: Actuator

The selected answer identifies the actuator as the component that directly implements actions based on signals received. In a control system, an actuator is responsible for converting the control signal into mechanical motion or physical action, such as moving a valve, turning a pump on or off, or adjusting the position of an element in response to commands from the controller. Actuators receive signals that determine their operation and execute the desired changes in the process being controlled. This makes them critical for the physical changes needed to maintain system conditions or achieve specific operational goals. Transmitter, sensor, and controller all play essential roles in the control process; however, they do not directly implement actions. The transmitter converts sensor measurements into a signal sent to the controller, while sensors are responsible for measuring physical phenomena and providing the necessary data. The controller processes these signals and decides what action should be taken, but it is the actuator that carries out these actions directly in the system.