In fluids with high adhesion and corrosion, chemical flood or flood diaphragm is used. In fact, these devices are used to prevent the direct contact of the measured fluid with the measuring part.
These sensors, usually metallic or of certain types of reactive polymers, are made of a flat or folded plate. The important advantages of diaphragms are the ability to protect other pressure measuring instruments against inappropriate conditions, such as high temperatures and corrosive fluids, as well as their high ability to seal. In other words, these types of sensors have much less need for other sealing equipment.