Intensity Differences of Copper Lines Depending on Impurity Contents

Abstract

Differences in copper line intensities depending on changes in minor impurity contents of anode copper have been observed. A statistical investigation of this phenomenon has been made. The base for this statistical investigation is 400 plates and corresponding analytical records from our routine spectrochemical work. For the excitation condition used, namely an interrupted arc, a regression equation for the depending of copper line intensity on impurity amounts has been calculated according to the method of least squares. Differences in thermal conductivity depending on impurity contents are regarded as the main cause for this phenomenon. This interpretation is confirmed by further investigations. The significant differences in copper line intensity between different anode copper specimens diminish as the excitation gets more spark-like. Less heat is deliberated, and thus the influence from the difference in thermal conductivity diminishes. The globule arc technique gives hardly any significant intensity difference for different specimens. This is also in conformity with the above explanation, as in this case the influence of thermal conductivity of solid copper is eliminated. Furthermore, the influence of the intensity variations on the spectrochemical results are discussed.