摘要 |
Two or more high-frequency microphones are used to determine where an individual spark or other excitation beam strikes a sample in an optical emission spectroscopy (OES) instrument. The position of the spark can be correlated with the elemental composition of the material in the sample vaporized by the spark. The microphones are placed appropriately in air around a sparker of the instrument, or appropriately on the sample, or on both the sample and in the air. Arrival times of sound from the spark to the microphones, or a difference in the arrival times, yields information, from which the position of the spark relative to the microphones, and hence the absolute position of the spark, is deduced, such as by triangulation. Optionally or in addition, a signal that indicates a time when the spark is produced is correlated with one or more spectra detected by a spectrometer, so a spectrum that results from the vaporized sample can be distinguished from a spectrum that results from heated gas above the sample.
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