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Spark and Arc Emission Sources


Spark and arc excitation sources use a current pulse (spark) or a continuous electical discharge (arc) between two electrodes to vaporize and excite analyte atoms. The electrodes are either metal or graphite. If the sample to be analyzed is a metal, it can be used as one electrode. Non-conducting samples are ground with graphite powder and placed into a cup-shaped lower electrode. Arc and spark sources can be used to excite atoms for atomic-emission spectroscopy or to ionize atoms for mass spectrometry. Arc and spark excitation sources have been replaced in many applications with plasma or laser sources, but are still widely used in the metals industry.

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