Abstract: A system for the introduction, monitoring and maintenance of pre-set levels of two or more gas components in a mixed gas chamber. The system has a micro-controller which monitors a pre-set level for each gas component in the mixed gas chamber using a plurality of sensors for each gas component. The system has an automated recovery with gas injection which automatically restore the level of each gas component to a pre-set level within the mixed gas chamber throughout all phases of operation of the mixed gas chamber, by injecting more gas of any gas component into the mixed gas chamber so as to maintain that gas component at the pre-set level whenever the pre-set level of that gas component is breached. The system has a redundant timed-sequence gas injection for all sequences of operation of the mixed gas chamber. A method of maintaining a pre-set level of two or more gas components in a mixed gas chamber using an automatic recovery with redundant time-sequenced gas injection is also provided.