Patent ID: 7624621

Claim:
A method for measuring gas permeation through a material comprising the steps of: a. forming a mixture of isotopic gases in a mixing enclosure, each of said isotopic gases corresponding to a different target gas for which permeation through said material is sought, each of said isotopic gases having a mass number different from that of said corresponding target gas; b. filling a first chamber of a permeation enclosure with said mixture of isotopic gases, said permeation enclosure comprising said first chamber and a second chamber, whereby said first and second chambers are separated by said material, and said isotopic gases enter said second chamber through said material; c. analysing said isotopic gases in said second chamber, so as to derive a permeation of each of said corresponding target gas through said material, and d. conducting a preliminary permeation analysis prior to said mixture formation comprising the steps of filling said first chamber with helium, and calculating a permeation of said helium through said material such that said material is preselected by excluding said material from subsequent analysis if said helium permeation is greater than a determined threshold.