US 7,320,243 B2
Methods and apparatus for detection of large leaks in sealed articles
Charles Perkins, Boston, Mass. (US); and Pieter N. Palenstijn, Plympton, Mass. (US)
Assigned to Varian, Inc., Palo Alto, Calif. (US)
Appl. No. 10/524,244
PCT Filed Jun. 09, 2004, PCT No. PCT/US2004/018413
§ 371(c)(1), (2), (4) Date Feb. 10, 2005,
PCT Pub. No. WO2004/111598, PCT Pub. Date Dec. 23, 2004.
Prior Publication US 2006/0156795 A1, Jul. 20, 2006
This patent is subject to a terminal disclaimer.
Int. Cl. G01M 3/20 (2006.01)
U.S. Cl. 73—40.7 13 Claims
OG exemplary drawing
 
1. Apparatus for leak detection comprising:
a first sealable chamber configured to receive a test piece containing a trace gas;
a second sealable chamber;
a first valve coupled between the first and second chambers;
a leak detector having a test port, the leak detector comprising an ion pump;
a trace gas permeable member coupled between the second chamber and the test port of the leak detector, the trace gas permeable member allowing the trace gas to pass and blocking other gases, liquids and particles;
a vacuum pump having an inlet;
a second valve coupled between the second chamber and the inlet of the vacuum pump; and
a controller to control the permeable member at a high trace gas permeability at a first pressure of about 100 millitorr in the second chamber and to control the permeable member at a low trace gas permeability at a second pressure in the second chamber, which is lower then said first pressure and is suitable for operation of said leak detector.