The pressure transmitter of type  series 652 are used for the long- and shortdistance transmission of electrical pressure-proportional signals. They are specially suited for the continuous level or flow monitoring of neutral  and slightly aggressive liquids and gases in heating, ventilation and process technology. The pressure or differential pressure to be monitored acts on a diaphragm, which in turn acts against a spring. As a result of the pressure action and the resultant diaphragm movement a permanent magnet fastened on the diaphragm moves in the direction of a hall sensor arranged outside the pressure case. This sensor emits an electrical signal which is  proportional to the magnetic field. The signal is linearized, compensated and amplified.