What is the function of a sensor in a control loop?

The function of a sensor in a control loop is to measure and relay information about process variables. Sensors are crucial components that provide real-time data on various parameters such as temperature, pressure, flow, or level. This information is essential for the control system to determine the current state of the process and make informed decisions regarding adjustments to maintain desired conditions.

In a control loop, the measurements taken by the sensor are sent to the controller, which then processes this data and compares it to the setpoint (the desired value). Based on this comparison, the controller calculates the necessary adjustments and sends commands to the actuator to bring the process variable back to the desired level. Without the sensor, the control system would lack the necessary information to function effectively, making it a fundamental element in achieving the overall control objectives.