This invention is a counting system that determines the absolute activity of radioactive gas samples non-destructively. Previous systems that determine absolute activity of radioactive gas samples are destructive techniques due to the design of the system (these systems retain an unquantifiable amount of gas after quantification is finished, making quantitative recovery of the sample impossible). The current invention is an improvement on the old systems that enables full and quantifiable recovery of the gas under analysis. This new system would make possible the use of these quantified gases in other processes such as stand-alone counting standards, or mixing the gas into a diluent as in a dilute radioactive gas calibration standard.