Patent US4489590A successfully refreshed from Google Patents.
US4489590A
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US
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Method and apparatus for gas detector calibration
Assignee: Delphian Corp
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Filing: 1982-01-25
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Granted: 1984-12-25
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Expires: 2002-01-25
Abstract
Abstract Methods and apparatus for applying calibrating gas to a combustible gas sensor, in which a calibration enclosure is formed mechanically upon application of pressurized calibration gas.
Inventors
- 👤 David M. Hadden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:37
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0006
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
126 words
A method for application of calibration gas to a combustible gas sensor which is normally positioned in a sampling recess and which is normally exposed to the ambient atmosphere through a porous sampling surface, comprising the steps of: applying pressurized calibration gas to the interior of a chamber which extends in response to said application of pressurized calibration gas and forming a calibration enclosure surrounding the sampling surface in mechanical response to said application by covering said recess in response to said application of pressurized calibration gas, introducing calibration gas into said calibration enclosure for calibration of said sensor, and stopping the application of pressurized calibration gas and opening the calibration enclosure to reexpose the sampling surface of the combustible gas sensor to the ambient atmosphere.
Claim 2
Independent Claim
126 words
A method for application of calibration gas to a combustible gas sensor which is normally positioned in a sampling recess and which is normally exposed to the ambient atmosphere through a porous sampling surface, comprising the steps of: applying pressurized calibration gas to the interior of a chamber which extends in response to said application of pressurized calibration gas and forming a calibration enclosure surrounding the sampling surface in mechanical response to said application by covering said recess in response to said application of pressurized calibration gas, introducing calibration gas into said calibration enclosure for calibration of said sensor, and stopping the application of pressurized calibration gas and opening the calibration enclosure to reexpose the sampling surface of the combustible gas sensor to the ambient atmosphere.
Claim 3
Dependent Claim
13 words
A method in accordance with claim 1 wherein said chamber is a bellows.
Claim 4
Dependent Claim
14 words
A method in accordance with claim 1 wherein said chamber is a telescoping chamber.
Claim 5
Dependent Claim
57 words
A method in accordance with claim 1 wherein said calibration gas is applied at a pressure in the range of from about 3 psig to about 50 psig, and wherein said calibration gas is introduced into said calibration enclosure at a flow delivery rate in the range of from about 0.5 to about 3 liters per minute.
Claim 6
Dependent Claim
89 words
Combustible gas detector calibration apparatus or the like, comprising, a combustible gas sensor having a porous sampling surface which is normally exposed to the ambient atmosphere, enclosure forming means responsive to the application of pressurized calibration gas for temporarily forming a calibration zone enclosing said sampling surface, and for opening said zone and reexposing said sampling surface upon ceasing the application of pressurized calibration gas, and means responsive to the application of pressurized calibration gas for conducting calibration gas through the calibration zone formed by said enclosure forming means.
Claim 7
Dependent Claim
89 words
Combustible gas detector calibration apparatus or the like, comprising, a combustible gas sensor having a porous sampling surface which is normally exposed to the ambient atmosphere, enclosure forming means responsive to the application of pressurized calibration gas for temporarily forming a calibration zone enclosing said sampling surface, and for opening said zone and reexposing said sampling surface upon ceasing the application of pressurized calibration gas, and means responsive to the application of pressurized calibration gas for conducting calibration gas through the calibration zone formed by said enclosure forming means.
Claim 8
Dependent Claim
45 words
A combustible gas detector calibration apparatus in accordance with claim 5 wherein said means for conducting calibration gas through the calibration zone provides a flow rate of calibration gas through the zone in the range of from about 0.3 to about 5 liters per minute.
Claim 9
Dependent Claim
80 words
A combustible gas detector calibration apparatus in accordance with claim 5 wherein said combustible gas sensor is positioned with means forming a recess and wherein said enclosure comprises a chamber which elongates in response to application of pressurized calibration gas to the interior thereof to cover said recess, said chamber including means for storing mechanical energy upon elongation which is sufficient to restore said chamber to a shortened position in the absence of pressurized gas applied to the interior thereof.
Claim 10
Dependent Claim
38 words
A combustible gas detector calibration apparatus in accordance with claim 7 wherein said chamber comprises a bellows or telescoping chamber adapted to introduce calibration gas at a pressure of less than about 0.5 psi through the calibration zone.
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) | 1987-12-25 | 1988-06-25 | 1988-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-25 | 1992-06-25 | 1992-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-25 | 1996-06-25 | 1996-12-25 | $7700.00 | Window Closed / Lapsed |