Pressure sensor e.g. for use in corrosive media - has non-metallic sensor element fitted in chemically resistant polymeric housing contg. expansion preventing tube

摘要

In a pressure sensor with a rotationally symmetrical non-metallic sensor element, which has a membrane mounted at a specific spacing on a base body and which is inserted with slight radial play in a cylindrical bore of a housing, the novelty is that (i) the housing (2) consists of a chemically resistant polymer (pref. a fluoropolymer); (ii) a radial sealing ring (4) is located between the housing (2) and the sensor element (1) in the region of the base body (1b); and (iii) an expansion preventing tube (5), having a lower thermal expansion coefficient than the housing, is located in axial register with the base body (1b) within the housing (2). Pref. the sensor element (1) is inserted into the front end of the cylindrical bore (6) of the housing (2) and seats, at the side opposiste to the membrane (1a) on a stepped region (7) of the bore. A smaller diameter passageway (8) connects coaxially with the cylindrical bore (6) and accommodates the sensor element leads (9) and opt. electronic circuitry (3) mounted on the back face of the base body (1b). ADVANTAGE - The sensor element provides a measurement signal independent of its fixing conditions, operates reliably over wide temp. range and can be used for measurements in corrosive media.