DC Arc in Emission Spectrography: I. Some Observations on the Influence of Lithium Compounds as Buffers

Abstract

The results of a series of experiments are reported in which buffers, consisting of a range of concentrations of various lithium compounds in graphite, were mixed with synthetic samples containing suitable concentrations of selected elements and the mixtures were then burned in the anode of a dc arc. Anode temperatures during the lifetime of the arc have been observed with the help of a thermistor bolometer and chart recorder. Arc-column temperatures were calculated from the relative intensities of the Mg lines 2783.6 and 3336.7 Å. From these observations, and the measured intensities of spectrum lines, conclusions are drawn regarding the effect of each buffer compound on arc and electrode temperature, vaporization rates, arc wandering, and general efficiency of the arc source.