A laboratory‐scale arc furnace encompassing a nonconsumable electrode and a cold hearth and operating at inert gas pressures of up to 20 bar is described. Using this equipment, weight losses due to volatilization when melting high vapor pressure metallic materials have been reduced to about 20% of those encountered with a conventional arc furnace operating at 1 bar. The arc furnace has been designed to be evacuable to high vacuum levels, as well as attaining high pressures, so that specimen purity can be retained by thoroughly evacuating and degassing the system prior to admitting inert gas and melting. Increases in gas pressure have been found to have a pronounced effect on the stability of the arc, especially at low arc currents, and to achieve minimum volatilization losses a balance is required between pressure and arc current for a particular sample.

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