The principle consists in the aspiration of the test solution into a dinitrogen monoxide/acetylene flame. Measurement of the radiation emitted by barium at a wavelength of 553,5 nm. The ionization of barium atoms in the flame is suppressed by addition of potassium chloride. The method is applicable to coating materials having soluble barium contents in the range of about 0,05 % (m/m) to 5 % (m/m). This method is the referee method in cases of dispute. This second edition cancels and replaces ISO 3856/3-1980, of which it constitutes a thorough revision.