A novel method of detecting contamination state on the hydrophobic surface

Partial surface conductivity is an ideal way for long-term contaminated degree monitoring of insulators. This method keeps the pollution layer from being destroyed in the measuring process. However, for hydrophobic surface, which is repelled from water, this method is hard to apply. In order to realize the measurement of partial surface conductivity on the hydrophobic surface, an improved measuring probe is proposed in this paper. The improved probe is composed of a handle and a cylindrical electrode. Based on the convenient turning over operation of this probe, the pollution layer can be wetted by dripping quantitative water into the probe and turning over the probe on the surface, which is more stable and reliable. The influence of water volume and measurement time of the new probe to the measuring results is elaborated in this paper. Test results demonstrate that partial surface conductivity increases as measurement time increases and finally becomes stable, and using too much or too little water both lead to the lessening of measuring results. It is noted that the suggested water volume is 0.06ml and the suggested measurement time is 2 minutes, in which case partial surface conductivity has good correlation with equivalent salt deposit density (ESDD) on artificial pollution samples. Contamination state can also be detected effectively on the hydrophobic surface. The method can be used for long-term monitoring and research studying of contaminated degree on the hydrophobic surface.