In a pneumatic transmitter, computing and comparison can be accomplished by which of the following methods?

The correct method for computing and comparison in a pneumatic transmitter is through the use of escapement valves. Escapement valves are mechanical devices that allow the controlled release of pneumatic pressure, enabling the measurement and comparison of various pressure signals in the system. This is crucial for ensuring that the transmitter can accurately process and relay information regarding the system's pressure levels.

These valves facilitate the operation of the pneumatic transmitter by providing a means to control the flow of air or gas under pressure, allowing for precise adjustments and stabilization of pressure readings. This comparison capability is essential for many applications, including monitoring system performance and ensuring that the operation remains within designated parameters.

While other methods such as using pressure sensors or digital signal processing might seem relevant, they serve different functions within maritime systems and do not perform the specific role of comparing and computing within the pneumatic framework as effectively as escapement valves. Pressure sensors primarily gather data rather than perform comparison tasks, and digital signal processing is typically associated with electronic systems rather than pneumatic control. The unique function of escapement valves makes them the suitable choice for the specified task in pneumatic transmitters.