Burning Properties of Electrodes for DC Arc Analysis

A series of tests have been made using two spectrographic electrode materials to evaluate differences in response to the dc arc over a wide variation in current (6 to 38 amp) Carbon anodes burn at a faster rate than graphite, but carbon is overloaded at a lower current density At high currents both materials approach the same burning rate The burning rates are dependent on the arc current, the cross sectional area, and the properties of the grade used Any one of the three variables can be partially compensated for by an equivalent change in the other two. The effects of burning rates on analytical results are discussed