IEC 62021-3:2014描述了两种测定未使用和使用过的电气非矿物绝缘油酸度的程序。方法A为电位滴定法，方法B为比色滴定法。该方法可用于指示非矿物绝缘油在氧化条件下使用时发生的相对变化，而不管产生的非矿物油的颜色或其他性质如何。酸度可用于未使用的非矿物绝缘油的质量控制。由于所用非矿物绝缘油中存在的各种氧化产物会产生酸性，且这些产物的腐蚀性能差异很大，因此该试验不能用于预测非矿物绝缘油的腐蚀性- 使用条件下的矿物绝缘油。

IEC 62021-3:2014 describes two procedures for the determination of the acidity of unused and used electrical non-mineral insulating oils. Method A is potentiometric titration and Method B is colourimetric titration. The method may be used to indicate relative changes that occur in non-mineral insulating oil during use under oxidizing conditions regardless of the colour or other properties of the resulting non-mineral oil. The acidity can be used in the quality control of unused non-mineral insulating oil. As a variety of oxidation products present in used non-mineral insulating oil contribute to acidity and these products vary widely in their corrosion properties, the test cannot be used to predict corrosiveness of non-mineral insulating oil under service conditions.