Research on contamination characteristics is of importance to external insulation design and power system operation. Artificial contamination test apparatus may be used to carry out insulator simulation contamination tests

and contamination characteristics of the insulator can be obtained in a relatively short period.Consequently

we developed a new artificial natural contamination test system in which wind

rain

fog

drying

voltage and grime concentration can be controlled independently

and then proposed test methods of artificial simulation of natural contamination.Artificial contamination test result shows that the contamination amount of insulator surface becomes saturated as the the contamination concentration increases

and the insulator surface contamination degree first increases and then decreases as the wind speed increases from 2.2 m/s to 7.5 m/s. The increment in contamination amount of insulator surface is relatively slow at the initial stage

speeds up at the medium stage

slows down and tends to the gradual saturation at the late stage as time becomes longer. Under the same operating environment

insulator contamination（from the serious to the low） is on cap and pin standard disc insulators

double-umbrella-type insulators

and triple-umbrella-type insulators.