Sulfur hexafluoride (SF6) gas is an inert insulating gas of high dielectric strength and thermal stability, often used in the power sector for insulating high voltage lines, circuit breakers, transformers and other switchgear equipments. As sf6 is an inert gas, it can’t cause corrosion but in the presence of moisture it will cause formation of highly corrosive acidic by-products, such as Hydrogen Fluoride (HF) and Sulfur dioxide (SO2). The amount and rate of damage of the SF6 equipment depends on the concentration of this byproduct formed, which is ultimately based on the quantity of water vapor present in the SF6 Gas. A higher concentration of water vapor presence allows for formation of a higher concentration of HF & SO2. Therefore, the importance of measuring the water vapor content of the gas used within the SF6 filled equipment is to ensure that corrosive electrolytes remain at low concentration level and substantially reduce the risk of damage and cost of maintenance.