The thickness of tin coatings on steel can be measured rapidly and nondestructively on either side of the sheet by application of a simple x‐ray technique. The method is based on the selection of an x‐ray beam of a wavelength that excites significant amounts of secondary radiation in the base metal but not in the coating. With this method, results were obtained that are comparable in accuracy and reproducibility to those obtained with the usual chemical methods for measuring the coating thickness of tin on steel.
The investigation placed emphasis on use of a commercial x‐ray spectrometer for measurement of tin coating thickness on a laboratory scale, but enough work was done to show that the principle used for measuring tin coating weights on steel is applicable to other coatings and to the continuous indication and control of tin coating weights on the electrotinning line. Such a unit has been designed and built.