Diaphragm pressure gauge is a type of pressure gauge that uses a diaphragm to measure pressure. The diaphragm is usually made of a thin, flexible material such as metal or elastomer. When pressure is applied to one side of the diaphragm, it deflects, causing a movement that is transmitted to a gauge indicator or transmitter.

Diaphragm pressure gauges are often used in applications where the pressure medium is aggressive or corrosive to the gauge material. The use of plastic materials, such as PP or PVDF, for the body of the gauge allows it to be resistant to corrosive materials.