Calibrating coating thickness gauges
Calibration procedure for coating thickness gauges
To calibrate a coating thickness gauge, you need a bare metal plate and a defined calibration foil. In the first step, you carry out a zero calibration without foil on the blank plate. In the second step, repeat the process, but with the foil between the plate and the probe. You have now carried out a two-point calibration which has programmed a stable characteristic curve into the device. You can check the characteristic curve with another control foil.
For devices with a combined probe, this calibration must be carried out once for the FE measurement and once for the NF measurement.
Our video shows the calibration of a TOP-CHECK coating thickness gauge.
Do you always have to calibrate the coating thickness gauge?
The coating thickness gauges from List-Magnetik are factory calibrated and do not necessarily have to be calibrated by the user. Coating thickness measurements on curved surfaces or on different base materials are an exception. Here, a two-point calibration should be carried out on an identical but uncoated object in accordance with ISO 2178.
Calibration material for the coating thickness gauge
To obtain the best result for a coating thickness measurement, it is best to use an uncoated area of the same geometry of the same material whose coating you want to test. Then the chemical composition of the material and its geometry, whether round or concave, perfectly match the measuring environment. If this is not possible, simply use our calibration plates supplied with the coating thickness gauge.
We supply everything you need. The “blue” plate is made of steel, the “red” plate is made of aluminum. With the 300 µm calibration foil, the optimum characteristic curve can be achieved for coatings up to 2 mm. For significantly thicker coatings, we recommend calibrating the coating thickness gauge with a 1 mm thick ceramic plate instead of the foil.
