Flashover voltage of artificially contaminated surfaces

Tests were carried out to analyse the influence of geometrical and physical parameters of a contaminating layer on the flashover of small flat surfaces. The wet-contaminant method was used, and the alternating and direct flashover voltages were related to different values and distributions of thickness, width and resistivity of the contaminant layer. The results show that the flashover voltage of a polluted strip depends strongly on the surface conductivity and slightly on the layer width and thickness. The nonuniformity of the parameters giving rise to the surface conductivity over the length of the polluting layer does not affect the flashover voltage.