In pneumatic control systems the control valve used as final control element converts

A control valve is a device that regulates the flow of a fluid. In pneumatic control systems, the control valve is used as the final control element to convert a pressure signal into a position change. The position change is then used to control the flow of the fluid.

The other options are incorrect because:

• Option A is incorrect because the control valve does not convert a pressure signal into an electric signal.
• Option C is incorrect because the control valve does not convert an electric signal into a pressure signal.
• Option D is incorrect because the control valve does not convert a position change into a pressure signal.