IFT in transformer oil stands for interfacial tension, which is a critical property that helps evaluate the oil’s cleanliness and its ability to resist contamination. A higher IFT value indicates that the transformer oil has a good ability to separate from water, preventing the formation of emulsions that can lead to reduced insulation performance. Regular monitoring of IFT in transformer oil is essential for maintaining the reliability and longevity of transformers, ensuring optimal electrical insulation and thermal conductivity.