We describe the calibration of a technique allowing quantitative measuremen
ts of industrial coatings with thicknesses as small as 10-20 nm, Wax films
doped with fluorescent rhodamine dye have been deposited by an electrospray
method onto an optically flat surface of aluminium-coated glass. The films
were of 220-450 nm peak thickness, which we measured with an optical profi
lometer using laser triangulation. Possession of a set of films allowing an
absolute calibration of the fluorescence intensity versus thickness to be
achieved for application in trials of the fluorescence method for measuring
coating thicknesses of 10-20 nm under industrial process conditions.