A pressure transmitter is a mechanical device that measures the expansive force of a liquid or gaseous sample.
Also known as a pressure transducer, this type of sensor is typically composed of a pressure sensitive surface area made of steel, silicon, or other materials depending upon the analyte’s composition. Behind these surfaces are electronic components capable of converting the applied force of the sample upon the pressure sensor into an electrical signal.
http://www.enbbonsensor.com/pressure-transmitter/