Patent ID: 6497156
Filing Date: 2002-12-24
Classification: G01N

Abstract:
A method for collecting a sample of gaseous constituents from a source of exhaust gases, the method comprising:collecting the sample in an inner bag defining a sample chamber and having a wall that bounds the sample chamber, the wall being made of a material that allows limited diffusion through the wall of at least one of the gaseous constituents in the sample; and collecting a control gas in an outer bag defining an auxiliary chamber at least partially bound by the wall such that diffusion between the sample chamber and the auxiliary chamber takes place through the wall, the outer bag having an outside wall that bounds the auxiliary chamber with respect to an outside environment and that is made of a material that allows limited diffusion through the outer bag outside wall of the at least one of the gaseous constituents, wherein said control gas controls the rate of diffusion of said at least one gaseous constituent through said wall.