Eddy Current Coating Thickness Measurement
Measurement of the thickness of non-conductive coatings on conductive base materials by measuring the impedance change of a coil. Eddy currents in the metal cause this change.
Physical-Chemical Mechanism of Action
Eddy current coating thickness measurement uses the phenomenon that an electric field induces eddy currents in a conductive material layer (e.g., steel). These eddy currents change the impedance of a nearby coil. The thicker the layer, the stronger the eddy currents and the larger the impedance measurement.
Metallurgical Relevance & Welding Risks
This measurement is especially important for checking layers like protective coatings or corrosion protection. Incorrect thicknesses can lead to missing protection or overly thick coatings, affecting the service life and behavior of the material under stress.
Workshop Practice & Action Instructions
To perform the measurement, place a coil near the metal part. The coil's impedance is then measured and compared to a reference value. For accurate results, it is important that the gauge is properly calibrated and that environmental factors like temperature and humidity are controlled.