What types of tests are typically described in a transformer oil tests PDF?

These documents usually outline sampling procedures and common condition tests such as BDV, moisture by Karl Fischer, acidity or neutralization number, dielectric dissipation factor (tan delta or power factor), resistivity, interfacial tension, color, and particle count. Many also include dissolved gas analysis for fault detection and furan analysis to assess paper insulation aging. Some programs add inhibitor content, corrosive sulfur screening, and PCB content tests for legacy assets. The PDF often maps tests to acceptance limits and maintenance actions.