Process pressure is transmitted through isolating diaphragms and oil fill fluid to a sensing diaphragm. The sensing diaphragm is a stretched spring element that deflects in response to differential pressure across it. The displacement of the sensing diaphragm, a maximum deflection of0.004 inch (0.10 mm), is proportional to the applied pressure. Capacitor plates on both sides of the sensing diaphragm detect the position of the diaphragm. The transmitter electronics convert the differential capacitance between the sensing diaphragm and the capacitor plates into a twowire, 4-20 mA dc signal and a digital output signal.