Method A outlines the classical procedure for quantifying the gases contained within transformer oil. Labs that began performing this test on their transformers have many years of historic data that remains important today. This data is used to track the changing conditions within a specific transformer, and by monitoring gas levels, judgments may be made as to when preventive maintenance should be performed. This analysis method has been in use for many years and is known to have some areas of weakness. This document describes the technological advances in Gas Chromatography that are employed here to incrementally improve the original method.