Laser-induced breakdown spectroscopy has been applied to the determination of carbon content in steel samples melted in a laboratory induction furnace. A focused Nd:YAG laser beam was used to generate the plasma on the liquid surface in argon atmosphere. The precision obtained is 10% for carbon contents in the range 150-1100 ppm, and the detection limit is 250 ppm. The present results show that this technique can be applied for direct composition determination in molten alloys.
C. Aragón, J. A. Aguilera, and J. Campos, "Determination of Carbon Content in Molten Steel Using Laser-Induced Breakdown Spectroscopy," Appl. Spectrosc. 47, 606-608 (1993)