MEASURING COATING THICKNESS - 1.

Any industrial coating thickness measuring and/or control method should meet the following requirements: It should be easy to implement, provide quick and easily interpretable results and permit measurements on large, small, and odd-shaped items. Whereas most classical thickness measurement methods are destructive, modern quality control calls in general for nondestructive, fast and reproduceably accurate methods which, in addition, should be capable of being automated and permit automatic data processing. An account is given of the most important nondestructive methods in current use; the only destructive method discussed is the coulometric method, as this method remains in general use in a fairly large number of organisations. Other methods, such as the thermoelectric and X-ray fluorescence have found little practical outlet for coating thickness testing in modern industry and are not therefore discussed.