What element is responsible for comparing current values to the setpoint?

The element responsible for comparing current values to the setpoint is the controller. In process control systems, the controller's primary function is to receive data from the sensors or transmitters, which provide real-time feedback about the current state of the system. The controller then compares this measured value against the desired setpoint.

When a discrepancy between the current value and the setpoint is detected, the controller calculates the necessary corrective action needed to minimize the error and maintain the process variable at the desired level. This action is typically executed through the final control element, which can modify process variables by adjusting valves, pumps, or other devices.

This process of continuous comparison and adjustment is essential for maintaining process stability and achieving desired outcomes in various industrial applications. The controller is the critical component that ensures the system functions as intended by maintaining control over the process through feedback mechanisms.