What are the IEC standards for transformer oil testing in power transformers?

The IEC standards for transformer oil testing in power transformers include IEC 60422, which outlines the methods for the maintenance of insulating oil, and IEC 61125, which specifies the test methods for the determination of the physical and chemical properties of insulating liquids. These standards ensure the quality and reliability of transformer oil, focusing on parameters such as dielectric strength, moisture content, and acidity, which are critical for the safe operation of power transformers.