Key focus
To understand what acidity measurements represent, how they are obtained, and how they should be interpreted in the context of transformer ageing.
Lesson description
This lesson examines acidity measurements (TAN) as an indicator of oil oxidation and ageing. It explains how acids form through oxidation in mineral oils and through hydrolysis processes in ester liquids, and why not all acids have the same significance.
The lesson reviews the main analytical methods used to determine acidity, including indicator titration, potentiometric titration, and spectroscopic estimation. It also explains how acidity relates to sludge formation, paper ageing, inhibitor depletion, and oil treatment requirements.
Practical interpretation strategies are emphasised, highlighting the need to assess acidity together with other parameters such as inhibitor condition, moisture content, interfacial tension, and oxidation stability.
Learning outcomes
- Explain what TAN represents and why acidity is an important ageing indicator.
- Distinguish between different types of organic acids and their impact on insulation systems.
- Compare common acidity test methods and understand their limitations.
- Recognise how acidity relates to oxidation, sludge formation, and treatment need.
- Interpret acidity together with other oil parameters for sound maintenance decisions.
Content of this lesson is fully vendor agnostic but it is sponsored by Ergon!
