How to test paint film coating?

The paint film coating has a protective and decorative effect on the substrate. Due to the different thickness of the coating, its protective performance will also be very different. In order to accurately assess the thickness of the film without damaging the performance of the film, you can use a film thickness measuring instrument to verify it. This article will bring you a method for measuring the film thickness.
How to verify the film thickness?
The film thickness measurement is to use a standard thickness gauge calibration thickness gauge to measure the coating thickness (so in most cases there is no problem of comparing the test piece). The standard test piece used for calibrating the instrument must have a clear value and meet the following requirements:
(1) Good rigidity, no significant elastic deformation occurs when the detection coil is pressed on it.
(2) Good bending performance. When used for measuring the thickness of the surface coating of curved parts, it should be able to form a good agreement with the curved surface of the object to be tested.
There are two main types of standard test strips for film thickness measurement: one is a film (sheet) without a substrate. This type of standard test strip can be covered on the substrate of various parts for instrument calibration, and has good applicability; The other type is a standard test piece with a base. The covering layer of this type of test piece is integrated with the base, but the use of this type of standard test piece has certain limitations.
The accuracy of eddy current thickness measurement is not only related to the uncertainty of the standard thickness diaphragm and the electromagnetic characteristics of the base material, but also closely related to the selection of the standard thickness test piece. The closer the standard thickness sheet used by the calibration instrument is to the thickness of the measured covering layer, the more accurate the measurement result will be. Therefore, when choosing an eddy current coating thickness gauge, special attention should be paid to the number of standard test pieces equipped with the instrument and the correlation between its thickness and the thickness range of the test object in actual work.