Relations between propagation velocity and line spectrum intensity of a local discharge on an electrolytic surface

An electrolytic solution surface was used to simulate the surface of wet polluted insulators. The solution was set in a Pyrex glass chamber. The air pressure in the chamber was changed from 27 to 101 kPa to make the condition of the insulators in altitudes. The resistivity of the solution was changed from about 170 to 740 Ω cm. As the applied voltages, impulse voltages of 2/80 μs, 10/800 μs and 100/2500 μs were used. A local discharge propagates on the solution surface when an impulse voltage is applied to the surface. Relations between the propagation velocity of the local discharge and the intensity of a line spectrum of light from the local discharge tip were examined. As a result, it was found that the influence of the air pressure on the relations is very small, the propagation velocity increases with the intensity of a line spectrum, and the propagation velocity for a given intensity of a line spectrum increases with the resistivity of the solution. Further, it was also found that the influence of the applied voltage waveform on the relations is small