Purification of Inert Atmospheres

Two systems have been developed for purifying inert atmospheres. One system, for helium, uses an activated charcoal bed at liquid nitrogen temperature to maintain levels of < 5 ppm each for oxygen and nitrogen and <1 ppm water vapor. The other system, for argon, uses heated titanium sponge and copper wool beds to keep nitrogen and oxygen, respectively, at < 20 ppm and 5 to 15 ppm, and water vapor at 5 to 25 ppm.