What types of transformer oil testing are performed for condition assessment?

Condition assessment typically combines electrical, chemical, and contamination focused tests. Core tests include DGA to detect fault gases, moisture by Karl Fischer, acidity, interfacial tension, dissipation factor, resistivity, and BDV. DGA testing is commonly aligned with methods such as ASTM D3612. Many programs also include inhibitor content, particle count, color, and furan analysis to assess paper aging. Results are interpreted using trend analysis and standard guidance, then linked to actions such as filtration, degassing, regeneration, leak repair, or planned outage inspection.