Patent ID: 7555934

Claim:
A permeation testing apparatus, comprising: a mass spectrometer; a controllable valve comprising an inlet and an outlet, the outlet coupled to the mass spectrometer; a test cell comprising: a first cavity; a first port arrangement configured to facilitate fluid communication between the first cavity and a test fluid source and between the first cavity and the inlet of the controllable valve; a second cavity; a second port arrangement configured to facilitate fluid communication between the second cavity and a challenge fluid source containing a challenge fluid; and a support arrangement configured to suspend a test film between the first and second cavities; a pressure sensing arrangement configured to sense total pressures in the first and second cavities; and a controller coupled to the controllable valve, the controller configured to controllably actuate the valve to deliver samples of a test fluid in the first cavity to the mass spectrometer while substantially balanced total pressures are maintained in the first and second cavities.