Discussion at Midwinter convention: Gaseous ionization in built-up insulation — II

F. M. Farmer: I just want to mention one thing you may be interested in. Dr. Whitehead has referred to the critical point in the curve between the dielectric losses and voltage. It is proposed to use this characteristic in a practical way in connection with paper-insulated cables. As you all know, a paper-insulated cable is an impregnated laminated structure, and we have always felt that an important element in the satisfactory operation of such a cable is thoroughness of impregnation. The question is, How are we going to tell when the insulation is thoroughly impregnated, that is, free from moisture and voids?