What are the technical aspects of how to check transformer oil level?

To check the transformer oil level, first ensure the transformer is de-energized and safe to access. Use a dipstick or sight glass, if available, to measure the oil level. The oil should be within the marked range on the sight glass or between the minimum and maximum indicators on the dipstick. Additionally, check for any signs of contamination or discoloration in the oil, as these can indicate potential issues with the transformer.