A two-section electrode for d c. arc analysis is described. The crater section is amorphous carbon and the holder is graphite. In this way the advantages of the burning properties of amorphous carbon are obtained and the disadvantage of its poor machinability is largely eliminated. The electrode found suitable for this adaptation is the cathode layer electrode which is used in a variety of analyses The two-section electrode requires no complex cutting tools and proper dimensions are easily maintained by the dimensional consistency of the carbon and graphite rods used in their construction. A summary of test results is given in table form.
J. W. Mellichamp and J. J. Finnegan, "A Combination Carbon-Graphite Electrode for DC Arc Analysis," Appl. Spectrosc. 11, 158-160 (1957)