GB/T 41633.3-2022 Active

This document describes two test methods for determining the acid value of unused and used non-mineral insulating oils for electrical purposes: potentiometric titration and colorimetric titration.
Note 1: In unused and used non-mineral insulating oils for electrical purposes, acidic components include organic acids, phenolic compounds, oxidation products, resins, organic metal salts, and additives, etc.
This document can be used to indicate the relative changes that occur in non-mineral insulating oils for electrical purposes during their use under oxidation conditions, regardless of whether their color or other properties have changed.
The acid value can be used for quality control of unused non-mineral insulating oils for electrical purposes. The oxidation products present in used non-mineral insulating oils for electrical purposes can affect their acid value, and these oxidation products have significant differences in corrosion characteristics, so this document cannot be used to predict the corrosiveness of non-mineral insulating oils for electrical purposes in use.
Note 2: The acid value results obtained by potentiometric titration may be the same or different from those obtained by colorimetric titration, but they are usually in the same order of magnitude.