Emerson
Emerson 1221 Differential Pressure Transducer
The most common and useful industrial pressure measuring instrument is the differential pressure transmitter. This equipment will sense the difference in pressure between two ports and produce an output signal with reference to a calibrated pressure range. The Emerson 1221 senses pressure change through the use of a capacitive pressure sensing capsule. As pressure changes, a change in capacitance occurs. This change is detected and converted to a low impedance, high level DC voltage signal by the signal-conditioning circuitry in the unit.