ASTM B487 – Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section
Significance and Use
4.1 Coating thickness is an important factor in the performance of a coating in service and is usually specified in a coating specification.
4.2 This method is suitable for acceptance testing.
1.1 This test method covers measurement of the local thickness of metal and oxide coatings by the microscopical examination of cross sections using an optical microscope.
1.2 Under good conditions, when using an optical microscope, the method is capable of giving an absolute measuring accuracy of 0.8 μm. Accuracy will determine the suitability of the method for measuring the thickness of thin coatings. Accuracy is dependent upon the setup of the microscope and preparation of the sample; 0.8 μm should not be taken as an absolute and instead as guideline.
1.2.1 Optical microscopes may use digital image capture devices and software to evaluate those images.