US3725658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for continuously detecting oxygen in a gas stream
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1971-01-18
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Granted: 1973-04-03
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Expires: 1991-01-18
Abstract
Abstract An apparatus and method for continuously detecting oxygen in a carrier gas stream. The apparatus employs a sensor film comprising a fluorescent material emitting from 3000 - 8000 A, dissolved in a carrier or solvent, the film being supported on a suitable substrate. Exciting radiation of about 2000 - 6500 A is applied to the film causing the fluorescent material to emit. Oxygen contained in the gas stream is rapidly dissolved into, and purged out of the film. The dissolved oxygen will quench the fluorescent emission, and the extent of quenching is proportional to the oxygen content of the gas stream. The dissolving and purging cycle occurs with sufficient speed to enable the oxygen analysis of breath to be determined on a real time basis.
Inventors
- 👤 C Stanley
- 👤 J Kropp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:15
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6428; G01N2021/6432; Y; Y10; Y10T; Y10T436/00; Y10T436/17; Y10T436/177692; Y10T436/178459; Y10T436/18; Y10T436/186; Y10T436/20; Y10T436/207497
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
201 words
An apparatus for continuously detecting oxygen in a gas stream which comprises: a sensor comprising a solvent and a fluorescent material dissolved therein; the fluorescent material having a fluorescent lifetime of about 1 X 10 9 to 1 X 10 6 seconds; said fluorescent material being capable of absorbing exciting radiation in the range of about 2000 - 6500 A and emitting in the range of about 3000 -8000 A; said fluorescent material having a fluorescent yield greater than about 1 percent; said sensor being supported on the outer side of a substrate as a stable and uniform film of about 2-80 microns thick; the response time of said film to equilibration of oxygen between the film and the gas above the film being a maximum of 0.1 seconds; a source of radiation to excite said film; said exciting radiation emitting in the 2000 - 6500 A range; the fluorescence of said fluorescent material being quenchable by oxygen proportionally to the amount of oxygen absorbed in said film; means to detect the changes in fluorescence of said fluorescent material, said changes being proportional to the amount of oxygen present in the gas stream; and means to record said changes in fluorescence.
Claim 2
Independent Claim
219 words
An apparatus for continuously detecting in a gas stream, a gas selected from the class of compounds consisting of oxygen, SO2, NO and NO3 which comprises: a sensor comprising a solvent and a fluorescent material dissolved therein; the fluorescent material having a fluorescent lifetime of about 1 X 10 9 to 1 X 10 6 seconds; said fluorescent material being capable of absorbing exciting radiation in the range of about 2000 - 6500 A and emitting in the range of about 3000 -8000 A; said fluorescent material having a fluorescent yield greater than about 1 percent; said sensor being supported on the outer side of a substrate as a stable and uniform film of about 2-80 microns thick; the response time of said film to equilibration of said gas between the film and the gas above the film being a maximum of 0.1 seconds; a source of radiation to excite said film; said exciting radiation emitting in the 2000 - 6500 A range; the fluorescence of said fluorescent material being quenchable by said gas proportionally to the amount of said gas absorbed in said film; means to detect the changes in fluorescence of said fluorescent material, said changes being proportional to the amount of said gas present in the gas stream; and means to record said changes in fluorescence.
Claim 3
Dependent Claim
24 words
The apparatus of claim 2 in which the solvent is selected from the class consisting of mineral oil, decalin, glycerol, Tetrahydrofuran, benzene and hexane.
Claim 4
Dependent Claim
22 words
The apparatus of claim 2 in which the fluorescent material is selected from the class consisting of pyrene, coronene, p-terphenyl and ovalene.
Claim 5
Dependent Claim
19 words
The apparatus of claim 2 in which the fluorescent yield of said compound is greater than about 10 percent.
Claim 6
Dependent Claim
162 words
A process for continuously detecting oxygen in a gas stream which comprises: passing said gas stream over a sensor supported on the outer side of a substrate as a stable and uniform film; said sensor film comprising a fluorescent material and a solvent therefor; said fluorescent material having a fluorescent lifetime of at least 1 X 10 9 seconds; said fluorescent material being capable of absorbing exciting radiation in the range of about 2000 - 6500 A and emitting in the range of about 3000 - 8000 A; irradiating said film with exciting radiation in the 2000 - 6500 A range; the fluorescence of said fluorescent material being quenchable by oxygen in proportion to the amount of oxygen in said film; equilibrating the oxygen between the film and the gas stream above it; detecting the changes in fluorescence of said fluorescent material, said changes being proportional to the amount of oxygen present in the gas stream; and recording said changes in fluorescence.
Claim 7
Dependent Claim
167 words
A process for continuously detecting oxygen in a gas stream which comprises; passing said gas stream over a sensor supported on the outer side of a substrate as a stable and uniform film; said sensor film comprising a fluorescent material and a solvent therefor; said fluorescent material having a fluorescent life-time of about 1 X 10 6 to 1 X 10 9 seconds; said fluorescent material being capable of absorbing exciting radiation in the range of about 3000 - 8000 A; irradiating said film with exciting radiation in the 2000 - 6500 A range; the fluorescence of said fluorescent material being quenchable by oxygen in proportion to the amount of oxygen in said film; the response time of said film to equilibration of oxygen between the film and the gas stream above it being at most 0.1 seconds; detecting the changes in fluorescent of said fluorescent material, said changes being proportional to the amount of oxygen present in the gas stream; and recording said changes in fluorescence.
Claim 8
Dependent Claim
183 words
A process for continuously detecting in a gas stream, a gas selected from the class consisting of oxygen, SO2, NO and No3 which comprises: passing said gas stream over a sensor supported on the outer side of a substrate as a stable and uniform film; said sensor film comprising a fluorescent material and a solvent therefor; said fluorescent material having a fluorescent life-time of about 1 X 10 6 to 1 X 10 9 seconds; said fluorescent material being capable of absorbing exciting radiation in the range of about 3000 - 8000 A; irradiating said film with exciting radiation in the 2000 - 6500 A range; the fluorescence of said fluorescent material being quenchable by said gas in proportion to the amount of said gas in said film; the response time of said film to equilibration of said gas between the film and the gas stream above it being at most 0.1 seconds; detecting the changes in fluorescent of said fluorescent material, said changes being proportional to the amount of said gas present in the gas stream; and recording said changes in fluorescence.
References Cited (Backward Citations)
US3105908A
Cited
US3271113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
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