The measurement of temperature in welding arcs

The most successful technique in the measurement of arc plasma temperatures has been one based on the Saha theory which describes the particle population of gases in a number of thermally excited states. The presence and variation in these states are detected by spectroscopic means. The general method, first introduced by Fowler and Milne in the measurement of star temperatures, was adapted to man-made arcs by Larenz and Bartels and has been progressively improved upon by a number of investigators. The method described in this paper is essentially that of Larenz and Bartels except that improved instrumentation has been applied to aid in the procurement of the spectroscopic data.