Bonded Foil Strain Gauges

Bonded foil strain gauge (BFSG) pressure transducers & transmitters have foil gauges made from materials such as Constantan which are bonded using industrial adhesives to a stainless diaphragm or beam which is the material which flexes in response to change in pressure.

Combining high stability and accuracy with robust mechanical properties, bonded foil strain gauges have earned a dominant role in sensor applications in the oil and gas industries.  As with any sensor technology, however, environmental factors such as temperature and humidity can affect these devices, introducing measurement drift in applications that require accurate, stable sensor performance. Through careful selection of sensors and associated materials, however, engineers can mitigate causes of drift in these devices and rely on them in diverse applications that depend on reliable measurement of load, torque, tension and pressure.

The foil strain gauge sensing element typically includes two or four foil strain gauges which are joined together into a wheatstone bridge circuit.

These types of pressure sensors are most suited to mid to high range pressure measurement and because the sensing diaphragm is stainless steel they are very robust and can withstand high dynamic pressure changes.