| 摘要 |
In a device for the monitoring and the prognosis of the failure probability of inductive proximity sensors (1) for the monitoring of the position of movable switch rails or rail components, in which the proximity sensor (1) has at least one coil (5) that is supplied by an oscillator (7), and the sensor current flowing by means of variable attenuation is measured and then fed to an evaluation circuit, characteristic lines (18, 22) of the sensor (1) are stored for the course of the sensor currents in dependency of the distance of the movable switch rails or rail components, i.e. the mechanical attenuation in an electric not additionally attenuated condition, and in an electric additionally attenuated condition. The measurement currents (22) corresponding to a mechanical attenuation condition (18), as well as to respective additionally electric attenuated condition are cyclic scanned. The respective measurement currents, or measurement reading pairs are fed to a comparison or evaluation circuit, in which the differences resulting from the characteristic lines are compared to the measured differences.
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