On the Properties of Tracking Resistance.

Surface electrical breakdown of insulating materials which are wet or dirty on the surface， are quite important from the standpoint of practical use， and in these case， the tracking resistance for the materials is not necessarilly proportional to arc resistance. In accordance， different test method in requiring the arc resistance must be adopted. To settle these problem， in the present paper，the previous methods are described and the new one is proposed. Next， the characteristics of these method were also compared with and the foundamental properties were evaluate