What tests are described in a transformer oil testing procedure PDF?

Such documents usually describe sampling methods, chain of custody, and a set of lab tests: BDV, moisture by Karl Fischer, acidity, dielectric dissipation factor, resistivity, interfacial tension, color, particle count, inhibitor content, and dissolved gas analysis. Many also include furan analysis to assess paper insulation aging and sometimes PCB screening for legacy assets. DGA is emphasized for diagnosing thermal and electrical faults through key gas patterns and trends.