Magnetic Property
Material ability to support the formation of a magnetic field within itself is measured relative to the permeability of free space. The value of target permeability determines how strongly a metal object concentrates the magnetic flux from an inductive sensor. This parameter influences both the signal amplitude and the effective range of the measurement.
Flux Amplification
High-permeability materials draw the magnetic field lines from the sensor coil into the metal, which increases the total inductance of the circuit. This effect dominates at low frequencies where eddy currents are weak. The resulting signal increase improves the measurement resolution for ferromagnetic targets.
Sensor Calibration
Specialized algorithms adjust the measurement parameters depending on whether the metal object is ferromagnetic or non-magnetic. Because the magnetic attraction opposes the eddy current effect, the calibration curves for these two material classes are completely different. The instrument must use the correct material profile to prevent significant errors in distance or thickness calculations.
These profiles are verified against known calibration blocks during instrument commissioning.
Dynamic Range
Saturation of the magnetic material occurs when the excitation field from the sensor is strong enough to align all the internal magnetic domains. This saturation limits the linear response of the sensor and reduces measurement accuracy at close ranges. System designers limit the coil current to prevent this saturation effect during operation.
