Radiant energy – Ionic separation or analysis – With sample supply means
Patent
1987-12-10
1989-07-04
Berman, Jack I.
Radiant energy
Ionic separation or analysis
With sample supply means
250281, 250289, 73 40, 73 407, 417152, 417153, 417154, H01J 4904
Patent
active
048453609
ABSTRACT:
A counterflow helium mass spectrometer leak detector in which a helium sample passes in a reverse direction through a diffusion pump to a mass spectrometer for measurement. The diffusion pump includes a conventional foreline and a second foreline provided with an ejector stage. A test sample is coupled from a test port through a bypass valve to the conventional foreline in a high sensitivity mode and is coupled to the second foreline in a low sensitivity mode. In the low sensitivity mode, the bypass valve is closed. An apertured control plate in the diffusion pump controls the relative reverse rates of duffusion from each foreline to the diffusion pump inlet by controlling the rates of vapor flow an annular pumping stages and to the ejector stage. The ejector stage includes a nozzle for directing a stream of vapor into the second foreline so as to inhibit flow of helium into the diffusion pump and establish a lower reverse diffusion rate at the second foreline. The disclosed configuration permits measurement of a large range of leak rates.
REFERENCES:
patent: 3342990 (1967-09-01), Barrington et al.
patent: 3520176 (1970-07-01), Becker
patent: 3626760 (1971-12-01), Briggs et al.
patent: 3690151 (1972-09-01), Briggs
patent: 4086031 (1978-04-01), Kuypers
patent: 4472962 (1984-09-01), Mennenga
patent: 4499752 (1985-02-01), Fruzzetti et al.
W. C. Worthington, "New Developments in Trapless Leak Detection", Research/Development, Nov., 1976.
"Introduction to Helium Mass Spectrometer Leak Detection", Varian Associates, Inc., 1980, pp. 26-45.
"New Dimensions in Leak Detection", VAC 1104C, 12/82, Varian/Lexington Vacuum Division.
Berman Jack I.
Cole Stanley Z.
McClellan William R.
Varian Associates Inc.
Yakes John C.
LandOfFree
Counterflow leak detector with high and low sensitivity operatin does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Counterflow leak detector with high and low sensitivity operatin, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Counterflow leak detector with high and low sensitivity operatin will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-854691