The current experimental work extends our calibration concept of separating the effects of absorption and fluorescence to the high - temperature superalloys. The new calibration procedure produces calibration equations which are valid over wide ranges of composition — a feature which is useful in the analysis of high - temperature superalloys . For the specimens considered, the elements iron, nickel, chromium, cobalt and molybdenum can be present at levels greater than 10%; while tantalum, aluminum, titanium, manganese, silicon and vanadium may be present at levels between 1 and 6%. The calibration for this group of alloys has required, in the past, a large number of standards; the number is reduced by judicious application of the given correction equations. Analytical errors can be limited to 1 to 2% in the use of this method.