EN 62021-3:2014

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Method A: Automatic potentiometric titration
5 Method B: Colourimetric titration
Annex A (informative) - Determination of acidity in
        non-mineral electrical insulating oils by
        photometric titration
Annex ZA (normative) - Normative references to
         international publications with their
         corresponding European publications

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.