1. When testing, it is necessary to pay attention to the metal magnetic properties and surface roughness of the standard plate should be similar to the test piece.
2. When measuring with ultrasonic thickness tester, the probe of the ultrasonic thickness gauge must be perpendicular to the surface of the sample.
3. When measuring, pay attention to the critical thickness of the base metal. If it is greater than the critical thickness, the measurement is not affected by the thickness of the base metal.
4. When measuring, pay attention to the influence of the curvature of the test piece on the measurement. Therefore, it is not reliable to measure on the curved surface of the test piece.
5. Before measuring, you need to pay attention to whether other electrical equipment around will generate magnetic field. Because if a magnetic field is generated, it will interfere with the magnetic thickness measurement method.