A method and apparatus are described for determining the helium content of gaseous mixtures. The work was done so that the Bureau of Mines could more accurately and economically analyze helium- containing natural gases, crude helium purchased from private industries, and helium in gases used in research. Activated coconut charcoal is utilized at liquid nitrogen temperature to adsorb components other than helium in the mixture. A transducer is then used to determine the helium pressure. Twenty or more analyses with a standard deviation of +/- 0.04 percent can be made in an 8-hour day.