FLUORESCENCE X-RAY ANALYZER

PURPOSE:To achieve a higher analysis at a quantitative analysis or the like by correcting counts considering the effect of higher order rays of a coexistent element. CONSTITUTION:As Cu other than P coexists in an analysis, higher order rays (4-order rays) of CuKalpha are detected with an X-ray detector 2 simultaneously together with PKalpha and an output thereof is inputted into an upper limit value selection circuit 6a and a lower limit value selection circuit 6b through an amplifier 4. Counts n2 and n1 of upper and lower limit counters 8a and 8b are transferred to a subtracter 10 and a difference n12 (=n1-n2) between counts n1 and n2 is calculated to extract a detection pulse alone based on X rays (PKalpha) of an element. An arithmetic device 12 calculates true counts n0 based on a special formula from values of counts n1 of the lower limit counter, a subtracting value n12 of the subtracter and a set dead time tau. Thus, a counting rate (CPS) is determined by dividing the counts n0 after corrected by a unit time (t) set with a timer 16.