Preparedby theTaskForceMemberson TestingIEEEInsulators, IEEEWorkingGroupon InsulatorContamination, LightningandInsulatorSubcommittee

The paper*summarizestheresultsof clean-fogtestsconductedby eleventask-forcelab- oratorieson a commonsuspension insulator, IEEEin- sulator.**The test seriesdone accordingto a specificset of guidelines, show considerable dis- persionin the fiftyper cent flashovervoltagebe- tweenthe laboratories.The significant parameters of theclean-fog methodthatinfluence thefiftyper cent flashover voltageare discussed.Morecontrols in testingare neededbeforethe formalization of the clean-fogmethod as a standardcontamination test forhighvoltageac insulatorscan bemade.