What is Eddy Current Technique?

The most common use of eddy current measurement is for non-conductive coatings over non-ferrous metals such as anodize or paint over aluminum.

This technique allows for an accurate reading with even very thin materials through elimination of the base effect.

How eddy current measurement works?

When a conductive material is subjected to an AC magnetic field from a probe, eddy currents occur in the material in proportion to frequency of the drive signal and conductivity of the material. The induced eddy currents generate an opposing magnetic field that alters the circuit reactance and the output voltage of the probe. The change in output voltage is used to calculate the coating thickness.

The iqualitrol gages use eddy current technology for measuring metallic coatings over ferrous substrates. Unlike the more common method, magnetic induction, eddy current technology is not limited by geometry, and it eliminates the need for calibration on the bare part.

The technology also comes with a scanning option that allows operators to continuously measure over large areas with one swift measurement. The feature calculates an average measurement, and it provides for an accurate reading for thickness over uneven or textured substrates, thus eliminating the need to take multiple readings.

Some gages include a detachable probe on a long, flexible cable, affording greater accessibility when measuring hard-to-reach surfaces. The adaptability of the instrument provides for maximum flexibility for measuring a variety of coating thicknesses.