July 22, 2020

Coating thickness gauge calibration

Correct coating thickness gauge calibration is essential to accurately measure bai. For calibration, a sample similar to the object to be measured later will be used, that is, at the same time, the standard sample and the object to be measured should have the same shape and geometry. Basically, the more standard samples of the measurement object match, the measurement result will be more accurate.
2. Make sure that the following properties of the calibration sample and the object to be measured match: - The radius of curvature of the surface - The substrate material (such as permeability, conductivity; in an ideal way, the standard sample and the measurement object should be the same material) - Substrate thickness - Measurement area size
3. Before starting the calibration, make sure that the calibration points, sensor tips and calibration templates are clean. If necessary, remove any deposits such as grease, metal chips, etc. Any impurities may affect the calibration and cause the calibration to be unstable.
4. Make sure to always find the same calibration position for each, especially the measurement of small parts and the measurement of corners. It is recommended to use a measuring bracket for small parts.
5. If using calibration foils, make sure they are placed on the plane of the substrate material. Air gaps under the foil must be avoided, as this will cause unstable readings. If it is curved aluminum foil, make sure they are placed on the substrate as shown below.
6. Precision thickness standards must be handled carefully. Any wear and tear of the thickness standard will be reflected in the wrong calibration value. Do not fold the calibration foil. Any buckling will cause an air gap under the film, resulting in unstable readings. Keep the thickness standard clean. Any grease, oil, dust or other accumulations must be avoided. The accumulation of aluminum foil will be regarded as the thickness and will cause a measurement error of the same value as the thickness of the accumulation. To give you a rough idea: a fingerprint accumulation is enough to cause an additional thickness error of several microns.
7. Stay away from strong magnetic fields during calibration.
8. More calibration standard thicknesses that can match the expected thickness will make calibration and measurement more accurate.
9. According to the electromagnetic induction method, measuring the thickness of the non-ferrous metal coating on the steel or iron substrate requires multi-point correction. The thickness standard sample must be made of the same metal as the object to be measured later.