Linear Calibration Analysis of Mixtures Containing the Same Cations from Insulators by Laser-Induced Breakdown Spectroscopy (LIBS)

Abstract

Detecting pollution on the surface of insulators in power transmission lines is an important part of ensuring the safe operation of the power grid. A mixture of various compounds containing Na and Ca are present in the pollution. The influence of mixing ratios on the calibration curves and relative spectral intensity was studied via Laser-induced breakdown spectroscopy (LIBS) by comparing different compounds containing the same cations at varying proportions. Na2CO3, NaHCO3, CaSO4, and CaCO3 samples containing different proportions of Na and Ca were prepared. The linear correlation coefficients (R2) for the Na and Ca calibration curves generated using various mixing ratios were analyzed. The results from the linear calibration curves for mixtures containing the same cations were not dramatically affected by the mixing ratio. These findings may greatly reduce the difficulty of LIBS analysis for complex contaminated components including pollutions. Various laser energy intensities had varying effects on the spectral characteristics of the elements measured. Reducing the laser energy intensity and selecting the Na II wavelengths improved the linear accuracy range of Na to greater than 43.4% at 1990.4 mJ/cm2 while increasing the laser energy intensity improved the linear accuracy of Ca and C.