Abstract: A sensor system is disclosed for the contactless measuring of the distance between a sensor body and an object. The sensor body contains an identification resistor, the resistance value of which can be interrogated by a control unit which is connected to the sensor body and which is located outside the sensor body. The interrogation makes it possible to determine whether the electrical connection between the control unit and the sensor body exists or is interrupted. If it is interrupted, this can be detected by the control unit in an unambiguous manner due to the missing connection to the identification resistor, and the control unit can generate an alarm signal in order to avoid faulty positioning of the sensor body relative to the object.

Abstract: In a measuring device which serves to measure a geometrical variable with the use of a sensor which is fed an alternating measuring current of constant amplitude by a regulated, phase-dependent current source. An alternating supply voltage and an alternating measuring voltage tapped by the sensor via a feedback path of the current source is superimposed in a superimposition stage, which belongs to the current source and downstream of which a reference element for determining the alternating measuring current is connected, to form a total voltage present at the reference element. In order to match a characteristic representing the relationship between the alternating measuring voltage and the geometrical variable to a prescribed characteristic curve, at least one of the alternating voltages fed to the superimposition stage is varied. The variation can concern both the amplitude and the phase.