A comparative study of dissolved gas analysis techniques: the vacuum extraction method versus the direct injection method

The dissolved gas analysis of transformer oils can now be accomplished without high vacuum extraction of the gases from the oil prior to the chromatographic analysis. The new direct injection technique allow the analysis to be conducted by injecting the oil directly into the gas chromatograph. The author presents comparative data for 100 samples that were analyzed by both the traditional vacuum extraction method and by the new direct injection method. The results indicate that the direct injection method. The results indicate that the direct injection method is a viable alternative technique that offers many advantages over the vacuum extraction method and is a valuable tool in the diagnostic process of evaluating the condition of power transformers. >