Degassing liquids principles, equipment and instrumentation

Aircraft hydraulic oil and electrical insulating oil are normally contaminated with dissolved air. Variations in temperature or pressure can convert dissolved air to free air bubbles in system. The bubbles degrade the system performance. Ground support equipment has been built that removes dissolved gases from liquids. Laboratory equipment can measure the amount of air in a liquid. The author has recently designed equipment that is installed on an aircraft to continuously remove dissolved air from the hydraulic systems. A device was demonstrated that can be installed in an airborne hydraulic system to visually indicate the dissolved gas content of the liquid in the system. A remote reading electrical instrumentation system is described.