The electric arc in argon and helium

Measurements of the electrical characteristics of arcs, such as the variation of voltage with current and with arc length, have been carried out by Ayrton,1 Nottingham,2 and Suits,3 and others for currents below 20 amperes and by Finkelnburg4 for carbon arcs for currents above 20 amperes. Most of the work has been done at atmospheric pressure. The great increase in the use of inert gases for arc welding has resulted in the publication of much valuable data on the behavior of arcs in these atmospheres under typical welding conditions. It appears, however, that there is a need for more quantitative information on the characteristics of the inert gas arc under controlled laboratory test conditions. In particular, this information is needed for arc currents in excess of 20 amperes and for gas pressures in the neighborhood of atmospheric such as pertain when the inert gas arc is used for welding.