Measuring methods for solubility of gases in insulation liquids

This paper introduces a new method and measurement approach to determine the solubility of key gases considered for DGA (dissolved gas analysis) technique in insulating liquids. For this purpose, a test set-up was designed and manufactured, which rules out the problems associated with application of the glass syringe method. Ostwald coefficient, which defines the solubility of gases in liquid phase, are measured at 25 °C and at the pressure of 1020 mbar for key gases in mineral oil. The measured values are consistent well with those presented in IEEE C57.104, which ascertains applicability of this method to reveal the gas solubility of conventional and emerging insulating fluids.