The schaffer diaphragm gauge is used for measurement of gas or liquids, and is well suited for use on corrosive, polluted or highly viscous mediums. These instruments are more reliable and easy to protect against overpressure than the Bourdon tube type The measuring element consists of one circular diaphragm clamped between a pair of flanges. It have a Diaphragm which displacement is transferred via a link to the movement.