In a tank level control loop, which statement correctly describes how the level transmitter and level control valve interact?

In a tank level control loop, which statement correctly describes how the level transmitter and level control valve interact?

• A. Level transmitter measures liquid height and outputs signal directly to the control valve, bypassing the controller.
• B. Level transmitter measures height but the valve position is adjusted by a separate manual control.
• C. Level transmitter uses a mechanical float to directly adjust the valve position.
• D. Level transmitter measures liquid height and outputs signal to the controller, which computes MV to drive the valve to maintain the setpoint.

Answer: (D)