WIRBELSTROMSENSOR

An eddy-current probe having a measuring coil is described, in the magnetic field of which coil the object to be detected is arranged, and having a reference coil as well as a sine-wave generator, whose output signal is applied to the coil, the output signal of which is subtracted by means of a subtractor whose output signal is applied directly to a first demodulator and, via a 90 DEG -phase shifter, to a second demodulator, the output signal of the sine-wave generator, shifted via a phase shifter having an adjustable phase angle, being applied to the demodulators as an additional signal, and the phase angle being chosen such that the interference signals in the complex impedance plane have a specific direction. The sensor according to the invention is characterised in that the output signal of the first demodulator is applied via an amplifier having an adjustable gain (a) and the output signal of the second demodulator is applied via an amplifier having an adjustable gain (b) to a further subtractor whose output signal (Utrig) is used, for example via a trigger threshold, as a measure of the object to be detected.