IDM Tool Kit for Rotary Equipment

Inductive sensors use the physical effect of the change of quality of a resonance circuit, which is caused by eddy current losses in leading materials. A LC-resonant circuit produces a high frequency alternating field. This field withdraws at the active surface of the sensor. If an electrically conductive material arrives into the field, then eddy currents occur according the induction law which extract energy from the resonant circuit. The peak-to-peak swing becomes smaller. This change is converted into a switching signal. From the operational principle it follows that all metals are seized – independently of whether they move or not.