How is transformer oil specific gravity measured?

Transformer oil specific gravity is measured using a hydrometer, which is a device that floats in the oil. The specific gravity is determined by reading the scale at the oil’s surface level. Alternatively, a digital density meter can be employed for more precise measurements. The specific gravity of transformer oil typically ranges from 0.8 to 0.9, indicating its density relative to water. Regular monitoring ensures optimal performance and safety of the transformer.