Electrical transformer transforms voltage from one level to another, usually from higher to lower voltage. Transformer uses oil as a coolant and insulator. Gases are formed within this oil due to natural aging and faults from oxidation, vaporization, oil breakdown, electrolytic action or insulation decomposition. Because the oil bathes every internal component, dissolved gases in the oil contain a lot of diagnostic information. Transformer is very expensive to replace, analyzing and monitoring these gases is critical to know when a transformer should be removed from service before catastrophic failure. Presence of individual gas components and their ratios indicate possible failure mode. GC2010D transformer oil dissolved gas analyzer just provides this analyzing and monitoring.