Abstract: A method for controlling an apparatus for exchanging a first gas contained in a sealed container for a second gas while the container is in a chamber. The method comprises the steps of withdrawing the first gas from the container for a predetermined period of time and approximating the head space volume of the container based directly or indirectly upon a change in headspace pressure in the container. The method further includes the step of withdrawing the first gas from the container and air from the chamber under conditions which are dependent upon the approximation of the headspace volume and which reduce the damage to the container due to pressure forces.

Abstract: An apparatus for exchanging a first gas contained in a sealed container for a second gas. The apparatus comprises a vacuum chamber for receiving the container and for maintaining a controlled pressure about the container, a gas exchange head for exchanging gas in the container while maintaining a seal between the container and the chamber, and a vacuum source coupled to the gas exchange head and to the vacuum chamber for evacuating the first gas from the container and air from the chamber. The apparatus further has a gas source for supplying the second gas, the gas source being coupled to the gas exchange head for supplying the second gas to the container, and a sensor for monitoring the pressure in the container during gas exchange.