How does an Eddy Current Proximity Probe work?
The way that the probe works is the following – the probe contains an inductance element (winding) that surrounds a ferrite core which when excited by a current generates a magnetic flux field. That magnetic field, in turn, generated eddy-currents on any adjacent metal target thereby causing losses in its flux density. The probe detects those losses in the magnetic flux density and when the probe is connected to either a probe driver or transmitter, it will generate an output voltage that is proportional to the distance (gap) between the probe tip and the target. The distance over which this voltage to gap proportion is linear, may be several thousands of an inch (.001″= 1 mil) or mils to as much as one inch.
