This standard covers specifications and test methods for unused mineral insulating oils, as deliv-ered. intended for use in transformers, switchgear and similar electncal equipment in which oil is required as an insulant or for heat transfer. These oils are obtained by distillation and refining of petroleum. Oils with and without additives are within the scope of this standard.
This standard does not apply to mineral insulating oils used as impregnants in cables or capacitors nor to hydrocarbon insulating liquids obtained by synthesis.
Note - Oils complying with the requirements of this standard, of the same class and containing no additives are considered to be compatible with one another and can be mixed in any proportion. This does not necessanly apply to oils containing additives and where the user wishes to mix such oils a check should be made to ensure that the mixture meets the requirements of this standard.