Quantitative electron microprobe analysis without standard samples

This review of the theory of pure element count rates measured by means of an electron microprobe analysis system with energy‐dispersive x‐ray detection defines the fundamental parameters needed for an analytical algorithm. Additionally, a presentation of these parameters by useful approximations is given. This is a basic requirement for the evaluation of theoretical expressions valid for characteristic x‐ray intensities of multielement samples. The derivation of these expressions is also given and from the results of numerous experiments it is concluded that (a) there is no systematic deviation of measured concentrations when compared with chemical analysis, (b) the quality expressed by absolute and relative errors of the analytical results is as good as that obtained by known methods that require standard samples, (c) the presented computer program, written for an HP 75C portable computer, gives the results of analysis within a calculation time of about 1 min and (d) the program is applicable to EDS and WDS both energy‐ and wavelength‐dispersive spectrometers and the range of application covers elements of Z ≥ 12.