How is transformer oil power factor measured?

Transformer oil power factor is measured using a capacitance bridge or a power factor tester. The process involves applying an AC voltage to a sample of the transformer oil and measuring the resulting current. The power factor is calculated by determining the ratio of the real power (watts) to the apparent power (volt-amperes) in the oil. This measurement helps assess the insulation quality and moisture content of the oil, which are critical for transformer performance.