What is the standard procedure for transformer oil sampling to ensure accurate testing and analysis?

The standard procedure for transformer oil sampling involves several key steps to ensure accurate testing and analysis. First, ensure that the sampling equipment is clean and free from contaminants. Next, take the sample from a representative location, typically from the drain valve or sampling port, while the transformer is operating. Fill the sample container to the appropriate level, avoiding air bubbles. Label the container clearly with relevant information, and store it in a cool, dark place until analysis. Proper documentation of the sampling process is also essential for traceability.