AbstractWe have developed a highly versatile, energy‐dispersive system for X‐ray fluorescence (XRF) analysis. Excitation may be achieved both by a Ag anode tube and by isotopic sources of241Am or55Fe. Radiation from the former may be either filtered and collimated, or monochromatized by a pyrolytic graphite cylindrical monochromator with further filtration through Pd foils. The system is currently being used both for quantitative fundamental‐parameter (absolute) analysis and for standard‐based determinations. A variety of mounts allows quantitative work on solid thick or thin samples, liquids, and specimens evaporated on 6.2 μm thick Mylar. Aside from single‐sample operation, a 90 position sample changer allows multi‐sample analysis, with great gain in work efficiency. The latter is automatically controlled by a PDP 11/05 computer, which also calculates results from the raw data from a Tracor Northern NS 880 energy‐dispersive system. Accuracies for analyses of steels (percent level) are ∼5%, while trace Zr/Hf analysis can be performed with 10–15% error; sensitivity for the lat