Development of the constraint equation method with theoretical coefficients in X-ray fluorescent analysis

Questions on increasing the accuracy and expanding the application field of calibration equations with calculated theoretical coefficients used in X-ray spectral analysis are discussed. We consider basic versions of the classical method of theoretical corrections 1] and their further development based on the use of intensity ratios of analytical lines as the analytical signal and also the use of absorption factors as theoretical coefficients. The methodic approaches developed are tested on a spectrometer of the SPECTROSCAN MAX series by the example of analysis of alloy steels.