Grand-Expert spectrometer for metal analysis: current status and analytical capabilities

This paper presents the characteristics of the modern Grand-Expert spectrometer for the analysis of metals and alloys. The spectrometer has an updated optical scheme and a new spectrum analyzer to solve a wide range of analytical tasks. The analytical capabilities of the spectrometer were investigated for the analysis of steels and high-purity copper and aluminum as an example. For each of the bases, the updated optical scheme made it possible to realize new opportunities for controlling the homogeneity of the sample material and the presence of micro-inclusions on the sample surface and for determining low impurity contents in the pure metal bases. The spectrometer uses a modern semiconductor spark generator with adjustable frequency, current intensity, and duration of individual spark pulses. Spectra of metal samples for individual spark pulses were obtained in real time for the investigated sample. The operation of the spectrometer in different modes and with different exposure times was tested to select the optimal parameters of calibration characteristics. Computer control provides full synchronization of the generator mode setting, argon feeding, and spectrum registration. For steels, we selected sparking modes with high stability of spectral line intensities and analyte concentrations, and for pure metals (copper and aluminum), modes providing low detection limits of impurity elements and good stability of the results.