Inductive Sensors
An inductive proximity sensor comprises an LC oscillating circuit, a signal evaluator, and a switching amplifier.
The coil of this oscillating circuit generates a high-frequency electromagnetic alternating field. This field is emitted at the sensing face of the sensor.
If attenuating material nears the sensing face, eddy currents are generated in the case of non-ferrite metals. In the case of ferromagnetic metals, hysteresis and eddy-current loss also occurs.
These losses draw energy from the oscillating circuit and reduce oscillation.The signal evaluator detects this reduction and converts it into a switching signal.
The terms "attenuated" and "unattenuated" are used to describe the two switching states of the inductive proximity sensors.
