What are the best practices for transformer oil sampling?

The best practices for transformer oil sampling include ensuring that the sample is taken from a representative location, preferably from the transformer’s sampling valve. Use clean, dry containers to avoid contamination, and fill the container to minimize air space. Label the sample clearly with date, time, and location. Conduct sampling during stable operating conditions, and follow standardized procedures such as ASTM D923 for dissolved gas analysis to ensure accurate results.