The HYDROCAL 1009-3 is designed for multi-gas-in-oil analysis on a bank of three single phase transformers located next to each other. This new wall mounted system allows for the individual measurement of Moisture in Oil (H2O) and the key gases Hydrogen (H2), Carbon Monoxide (CO), Carbon Dioxide (CO2), Methane (CH4), Acetylene (C2H2), Ethylene (C2H4), Ethane (C2H6) and Oxygen (O2) dissolved in transformer oil utilizing a sampling system that samples oil from each tank via three separate oil channels expertly engineered to provide negligible mixing of oil.