a flow - through vacuum degassing unit for degassing a liquid includes a vacuum chamber adapted to be connected to a source for creating a vacuum in the chamber , an inlet and an outlet connection for admitting and discharging liquid to be degassed , a tube for conducting the liquid through the chamber , wherein the tube is a gas permeable polymeric resin material , and a control circuit for operating the source for creating a vacuum in the chamber responsive to a sensed vacuum level in the chamber .