The coating thickness can be determined by the fluorescence of the item induced by an X-ray source.
Our lab is equipped by a calibrated instrument for the whole range of coatings and substrates.
In fact the coating crystalline lattice in contact with a substrate, once irradiated by an X-ray radiation, can re-emit an higher wave-length radiation in proportion to its dimensions and to the type of the involved atoms.
After a fair calibration with standard samples it is possible to relate the emitted energy to the protective film thickness.
The instrument presents an high resolution and an high sensibility with very low revealing limits (about 0,20 microns for the all bands).
It does not affect nor damage the analysed item.
For further information: UNI 3497/01 www.uni.com