How is transformer oil acidity measured and controlled?

Transformer oil acidity is measured using the Neutralization Number (NN), which quantifies the amount of acid present in the oil. This is typically determined through titration with a standardized alkaline solution. To control acidity, regular sampling and testing are essential. If acidity levels exceed acceptable limits, oil can be treated through filtration or chemical neutralization to remove acidic compounds, ensuring optimal performance and longevity of the transformer.