Disclosed is a pressure gauge comprising a pressure sensor, a pressure transmitter connected upstream of the pressure sensor and having an isolation diaphragm, the outer side of which can be supplied with pressure and under which a pressure receiving chamber is enclosed, and comprising a hydraulic pressure transmission path connected to the pressure receiving chamber and filled with a pressure transmitting fluid. The diaphragm seal comprises a deflection device actuated by a controller connected to the pressure sensor and/or to a temperature sensor, and which is designed to exert a force on the isolation diaphragm, or on an element connected to the isolation diaphragm, said force deflecting the isolation diaphragm in the direction of its diaphragm bed, at times that are determined by the controller and that are based on a pressure measured continuously by the pressure sensor and/or a temperature measured continuously by the temperature sensor.