Eddy Current measuring method

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The prerequisite for this is a non-magnetic base material and a magnetic/non-conductive coating.

This is how Eddy Current measuring works.

This measuring method uses probes with or without ferrite core. A coil is wound around these, through which a high-frequency alternating current flows. This creates a high-frequency alternating magnetic field around the coil.

If the probe pole comes close to a metal, so-called eddy currents are induced in this metal. This also generates an alternating magnetic field. Since this second magnetic field is opposite to the first one, the original magnetic field is weakened. The extent of this weakening depends on the distance between the pole and the metal base material. For coated parts, this distance corresponds to the coating thickness.

Where is this process used?

Electrically non-conductive, non-magnetic coating materials
- e. g. paint, lacquer or plastic coatings on electrically conductive non-ferrous metals
- e. g. anodized coatings (anodizing) on aluminum
- Calibration: Instruments must be calibrated for the specific material type and thickness range for accurate results.
- Surface Condition: The surface of the material must be smooth, clean, and free from any contaminants, such as dust or oil, which could affect measurements.
- Temperature Stability: Extreme temperature variations can impact the readings, so stable environmental conditions are recommended.