Diaphragm seals are used to protect the pressure measuring instrument from aggressive, adhesive, crystallising, corrosive, environmentally hazardous or toxic media.
A diaphragm made of the appropriate material provides for the separation from the medium to be measured. Thus even the most difficult measuring requirements can be met by combining measuring instruments with diaphragm seals.

A fluid inside the system, which can be chosen to suit the particular application, hydraulically transmits the pressure to the measuring instrument. Almost limitless application possibilities exist due to the large number of available variants, such as diaphragm seal designs or materials.

The type of process connection (flange, threaded and sterile connection) and the basic method of manufacture are important design differentiation criteria. For further technical information on diaphragm seals and diaphragm seal systems see IN 00.06 "Application, operating principle, designs".