A differential pressure sensor designed to detect a change in pressure as the difference between two applied pressures. A differential pressure sensor employs a dual diaphragm with each diaphragm linked to a common central gauged element (foil-based sensors) or silicon substrate (silicon-based sensors). If both applied pressures are equal, both diaghragms are balanced and the reading shows zero. But if either diaphragm sees a different pressure from the other, this differential pressure is transmitted to the gauged element.

As the gauged element or silicon substrate is deflected, so the pages register a change in resistance. The bridge circuit identifies the resulting change in electrical resistance as a change in applied pressure to the sensor.

Differential pressure sensors are commonly used to measure the rate of flow in a pipe. By monitoring the pressure drop on either side of an orifice plate, the mass flow rate of the fluid in the pipe can be determined. Consult the Pressure reference Chart to compare how the various pressure sensors reference pressure.

Silicon Versus Bonded Foil Sensor Comparison Chart