A low-cost laser-induced breakdown spectrometer for multielements analysis of solid iron steel samples

摘要

A low-cost laser-induced breakdown spectrometer designed and equipped with Q-switch Nd:YAG laser at 1064 nm, 750mm Paschen - Runge polychromator and photomultiplier(PMT) detectors, can be used for analyzing multielements simultaneously in complex iron and steel matrices in short time. Gate control unit with the minimum gate width of 25 ns and minimum gate delay of 300ns is utilized to acquire a signal only when the S/N ratio is at an optimum level. At laser power density of 2.5～6.9G W/cm2, a gate delay time of 2 us, gate pulse width of 10us and Ar flow rate of 0.41/min , high sensible and stable spectral intensity was obtained for thirteen elements in iron & steel sample. Calibration graphs for thirteen elements were established under optimized conditions, and the accuracy of the developed methods was evaluated by using two certified reference samples. Quantitative results showed that there was no significant difference between certified and found values. The reproducibility was in the range 1～6% RSD for certified reference sample.