The inductive sensor is a simple enough device at the fundamental level. It is simply a coil of wire with a current passing through it. It completely ignores most objects which pass near this coil. However, when a metallic object passes near it, it acts as a core material in the inductive loop which increases its inductance significantly. Most non
-metallic objects have a negligible effect on its inductance. The complex part of the sensor is the sensing circuitry which detects this change in inductance by monitoring the electric current in the loop. When the inductance changes enough, it triggers the sensor`s output, which sends a signal to some other machine to do whatever it is it is supposed to do when a metallic object is near the sensor.