Which standard should be followed when removing a sample of insulating liquid?

When removing a sample of insulating liquid, the correct standard to follow is ASTM D923. This standard specifically provides guidelines for the sampling of insulating liquids used in electrical equipment, such as transformers and switchgear, ensuring the accuracy and reliability of the sampled material for testing purposes. It addresses various factors that can affect sample integrity, including the environment, sample handling, and storage conditions, which are critical for obtaining trustworthy analytical results that reflect the condition of the insulating fluid.

Following ASTM D923 allows technicians and maintenance personnel to adhere to best practices in sampling technique, minimizing the risk of contamination or degradation of the sample. This ensures that subsequent analyses, such as tests for moisture content, dissolved gases, or other contamination, yield valid data, enabling accurate assessments of the equipment's condition and performance.