Breakdown and prebreakdown phenomena in insulating liquids at large distances

The authors present an investigation of the breakdown and prebreakdown behavior of two insulating liquids; a benzyl-toluene and a mineral oil, in point-plane electrode geometry under positive polarity. To properly evaluate the breakdown voltage as a function of interelectrode distance (and voltage), it was necessary to utilize more statistically based methods than are usually used. In this light, a better and more realistic comparison of dielectric strengths between liquids can be made. The authors also investigate the length a streamer will travel across the interelectrode distance before stopping, for voltages lower than the breakdown values. These lengths are plotted nondimensionally against voltage for both liquids