A true gage pressure sensor is a bonded, foil strain gauge-based pressure sensor designed to measure applied pressure referenced to current atmospheric pressure.

A true gage pressure sensor employs a dual diaphragm. One side of the diaphragm has the pressure to be measured applied while to second diaphragm, required to prevent moisture and other air particles from entering the sensor is vented to reference the current atmospheric pressure.

A true gage pressure sensor operates in the same way as a bonded, foil strain gauge-based pressure sensor. As pressure is applied to a diaphragm, pressure is transmitted to a gauged element via a mechanical connection, such as a bolt. As the gauged element is deflected, strain gauges, which are bonded to the element, reflect this as a change in resistance. The bridge circuit identifies the resulting change in electrical resistance as a change in applied pressure to the sensor.

Note: Honeywell is one of only a few companies offering true gage pressure transducers. It also unique in offering a second diaphragm that protects the sensor from corrosion and damage by venting to air with humidity and dirt.