IEC 62021-2-2007 绝缘油.酸性的测定.第2部分:比色滴定法

标准号：IEC 62021-2-2007
中文标准名称：绝缘油.酸性的测定.第2部分:比色滴定法
英文标准名称：Insulating liquids - Determination of acidity - Part 2 Colourimetric titration
标准类型：E38
发布日期：1999/12/31 12:00:00
实施日期：1999/12/31 12:00:00
中国标准分类号：E38
国际标准分类号：29.040.10
适用范围：This part of IEC 62021 describes a procedure for determination of the acidity of unused andused electrical mineral insulating oils.NOTE 1 In unused and used mineral insulating oils, the constituents that may be considered to have acidiccharacteristics include organic acids, phenolic compounds, some oxidation products, resins, organometallic saltsand additives.The method may be used to indicate relative changes that occur in a mineral insulating oilduring use under oxidizing conditions that may or may not be shown by other properties of theresulting mineral oil.The acidity can be used in the quality control of unused mineral oil.As a variety of oxidation products present in used mineral oil contribute to acidity and theseproducts vary widely in their corrosion properties, the test cannot be used to predictcorrosiveness of a mineral oil under service conditions.NOTE 2 The acidity results obtained by this test method may or may not be numerically the same as thoseobtained by potentiometric methods, but they are generally of the same magnitude. The potentiometric methoduses an endpoint at pH 11,3 to ensure titration of all species, whereas the colourimetric methods uses an indicatorchanging colour at approximately pH 9,5. This may lead to slightly higher results for oils with acidities above0,3 mg KOH/g oil when using the potentiometric method.