US3837228A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tracer gas-permeable probe for leak detectors
Assignee: Vacuum Instrument Corp
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Filing: 1973-04-09
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Granted: 1974-09-24
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Expires: 1993-04-09
Abstract
Abstract In a leak detector system which employs a predetermined tracer gas, such as helium, the detector probe is provided with a plastic film which is selectively permeable to the tracer gas in preference to all other atmospheric gases. All detected gases must pass through the film in order to reach the detection element. Because of the selective permeability of the film the probe can assume substantially any size and configuration and can be employed without preparing a contaminant free environment. Moreover, the selectivity of the probe film permits the detection element to be a simple flow monitoring device rather than a mass spectrometer or other gas-distinguishing apparatus.
Inventors
- 👤 R Nemeth
- 👤 W Dugger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 19:34
CPC Classifications
G; G01; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/202; G01M3/205
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
A mass spectrometer leak detector for detecting leakage of a predetermined tracer gas from an enclosure to be tested which is internally pressurized with said tracer gas, said leak detector comprising: mass spectrometer means for detecting the presence of said tracer gas therein; a flow path having its outlet end connected to deliver gas flow to said mass spectrometer means and an inlet end, said inlet end having a substantially greater cross-section than said outlet end and being covered with a thin film material having a relatively high permeability to said tracer gas; and means for establishing a pressure differential across said flow path which tends to draw gases into said flow path.
Claim 2
Dependent Claim
113 words
A mass spectrometer leak detector for detecting leakage of a predetermined tracer gas from an enclosure to be tested which is internally pressurized with said tracer gas, said leak detector comprising: mass spectrometer means for detecting the presence of said tracer gas therein; a flow path having its outlet end connected to deliver gas flow to said mass spectrometer means and an inlet end, said inlet end having a substantially greater cross-section than said outlet end and being covered with a thin film material having a relatively high permeability to said tracer gas; and means for establishing a pressure differential across said flow path which tends to draw gases into said flow path.
Claim 3
Dependent Claim
37 words
The leak detector according to claim 1 wherein the permeability of said thin film to said tracer gas is at least two orders of magnitude greater than the permeability of said thin film to other atmospheric gases.
Claim 4
Dependent Claim
41 words
The leak detector according to claim 1 wherein said inlet end is fixed in position, and further comprising conveyor means for successively transporting a series of said internally pressurized enclosures to be tested past the inlet end of said flow path.
Claim 5
Dependent Claim
49 words
The combination according to claim 3 wherein said inlet end of said flow path is located adjacent said conveyor means and wherein said series of enclosures are positioned on said conveyor means such that a specified region of each enclosure passes proximate said inlet end of said flow path.
Claim 6
Dependent Claim
65 words
The combination according to claim 3 wherein said inlet end of said flow path is in the form of a hood in which said thin film corresponds to at least one internal wall, and wherein said conveyor means is arranged to transport said enclosures beneath said hood such that tracer gas leaking from said enclosures is drawn into said flow path through said thin film.
Claim 7
Dependent Claim
17 words
The combination according to claim 5 wherein all internal walls of said hood constitute said thin film.
Claim 8
Dependent Claim
43 words
The combination according to claim 1 wherein said enclosure to be tested has a first dimension along which leak detection is to be performed and wherein said inlet end of said probe has at least one dimension substantially equal to said first dimension.
Claim 9
Dependent Claim
87 words
A leak detector for detecting leakage of a predetermined tracer gas into an evacuated closed container under test, said leak detector comprising: an enclosure for said container under test, at least one wall of said enclosure being formed from a thin plastic film which has a significantly larger permeability to said tracer gas than to other atmospheric gases; means for flowing said tracer gas into said enclosure through said one wall; and means for monitoring the content of said tracer gas in said evacuated unit under test.
Claim 10
Dependent Claim
87 words
A leak detector for detecting leakage of a predetermined tracer gas into an evacuated closed container under test, said leak detector comprising: an enclosure for said container under test, at least one wall of said enclosure being formed from a thin plastic film which has a significantly larger permeability to said tracer gas than to other atmospheric gases; means for flowing said tracer gas into said enclosure through said one wall; and means for monitoring the content of said tracer gas in said evacuated unit under test.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |