Sparkover Characteristics of Long Fog-Contaminated Air Gaps

The paper constitutes a systematic experimental investigation into the effect of fog on the sparkover characteristics of rod-plane gaps with special reference to power frequency voltages. The tests covered gap spacings in the range of 15-400 cm. Special care was taken to separate the effects of the mode of voltage application from those due to physical changes in the gap under investigation. Tests were also performed under a variety of air humidity conditions and under artificial rain. Finally, tests with switching impulses and direct voltage of both polarities are reported.