The Analysis of Metals at a Distance Using Laser-Induced Breakdown Spectroscopy

Laser-Induced Breakdown Spectroscopy (LIBS) has been used to provide a rapid analysis of metals at distances between 0.5 and 2.4 m from the focusing lens and light-collection optics. The laser sparks were generated with the use of pulses from a Nd: YAG laser, and the spark light was collected by the use of a fiber optic cable. The wide acceptance angle of the cable relaxed the constraint that the spark be formed at a precise location for maximum light-collection efficiency and allowed the detection system to be placed remote from the sample. The identification of the main elemental component of eight metals using lines over a 40-nm spectral region was demonstrated by the use of a single laser pulse to record each spectrum. The accuracy and precision of analysis of the minor constituents of steel were determined, and the effect of surface contamination was examined. The application of LIBS to some industrial monitoring situations is discussed.