EN 62021-2:2007

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
   5.1 Titration reagent
   5.2 Titration solvent
   5.3 Potassium hydrogen phthalate, primary standard
   5.4 Standard hydrochloric acid solution
   5.5 Alkali Blue 6B indicator solution
   5.6 Cobalt nitrate solution
6 Apparatus
   6.1 Titration vessel
   6.2 Stirrer
   6.3 Burette
7 Sampling
8 Procedure
   8.1 Standardization of alcoholic potassium hydroxide
        solution
   8.2 Blank titration
   8.3 Sample titration
9 Calculation of results
10 Precision
   10.1 Repeatability
   10.2 Reproducibility
11 Report
Annex A (informative) Determination of acidity in electrical
        insulating oils by photometric titration
Annex ZA (normative) Normative references to international
         publications with their corresponding European
         publications

Describes a procedure for determination of the acidity of unused and used electrical mineral insulating oils. The method may be used to indicate relative changes that occur in a mineral insulating oil during use under oxidizing conditions that may or may not be shown by other properties of the resulting 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 these products vary widely in their corrosion properties, the test cannot be used to predict corrosiveness of a mineral oil under service conditions.