R22 Blister testing of magnet wire

Not long after the introduction of refrigerant 22 (mono-chlorodifluoromethane, or R22) to the refrigeration industry, blistered magnet wire was found in opened hermetic units, and blister testing began. Although a formal standard has not issued, certain test procedures became and remain popular. These methods are inadequate today and a new approach to blister testing is proposed in this paper. A review of the phenomenon of blistering and of the various tests serve as an introduction.