The electric arc in argon and helium

THE EXACT NATURE OF THE MECHANISM of the high-current electric arc is not yet understood clearly even though the arc has been used and studied for the past century and a half. Much of the difficulty in the interpretation of arc data has been associated with the complexity of the test conditions. An example of this is found in much of the data reported on welding arcs∗∗∗ in air. Such arcs are drawn in an atmosphere composed of a mixture of several gases (some of which are very active chemically) with electrodes which are usually of complex metallic and chemical structure.