New IEEE Standard - Inactive-Reserved. Tests and evaluation procedures for silicone transformer fluid are recommended. Criteria for maintenance and methods of reconditioning silicone fluid are described. The aim is to assist the transformer operator in evaluating the silicone insulating fluids in transformers, fluid received from the manufacturer for filling transformers at the installation site, and fluid processed into such transformers, as well as in maintaining the properties of silicone fluid in operating transformers.