US3679899A
Expired / Lapsed
US
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Nondispersive gas analyzing method and apparatus wherein radiation is serially passed through a reference and unknown gas
Assignee: National Aeronautics and Space Administration
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Filing: 1971-04-16
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Granted: 1972-07-25
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Expires: 1991-04-16
Abstract
Abstract A nondispersive gas analyzing means including a first variable volume container for receiving a quantity of a reference gas, a second variable volume container for receiving a quantity of an unknown gas to be analyzed, means for differentially varying the density of the gas in the first and second containers, means for causing radiation to pass serially through the first and second containers, a radiation detector for detecting the intensity of the radiation emerging from the second container and generating a radiation signal responsive thereof, and electronic means for selecting and displaying a particular component of the radiation signal which is uniquely related to the amount of gas of the reference type present in the unknown gas.
Inventors
- 👤 John Dimeff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:08
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/35; G01N21/3504; G01N21/3518
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
142 words
A nondispersive gas analyzing apparatus, comprising: means forming a first chamber for containing a reference gas; means forming a second chamber for containing an unknown gas; radiant energy source means for causing radiant energy to pass serially through said first chamber and said second chamber; first modulation means for modulating the radiant energy passing through said first chamber at a first frequency; second modulation means for modulating the radiant energy passing through second chamber at a second frequency; radiant energy sensing means responsive to the radiant energy passing through said chambers and operative to develop an electrical signal containing a plurality of signal components related to the constituents of said gases; and signal detector means responsive to said electrical signal and operative to select therefrom a particular signal component relating to the presence of a reference gas constituent in said unknown gas.
Claim 2
Dependent Claim
142 words
A nondispersive gas analyzing apparatus, comprising: means forming a first chamber for containing a reference gas; means forming a second chamber for containing an unknown gas; radiant energy source means for causing radiant energy to pass serially through said first chamber and said second chamber; first modulation means for modulating the radiant energy passing through said first chamber at a first frequency; second modulation means for modulating the radiant energy passing through second chamber at a second frequency; radiant energy sensing means responsive to the radiant energy passing through said chambers and operative to develop an electrical signal containing a plurality of signal components related to the constituents of said gases; and signal detector means responsive to said electrical signal and operative to select therefrom a particular signal component relating to the presence of a reference gas constituent in said unknown gas.
Claim 3
Dependent Claim
42 words
A nondispersive gas analyzing apparatus as recited in claim 1 wherein said first modulation means includes means for periodically varying the volume of said first chamber, and said second modulation means includes means for periodically varying the volume of said second chamber.
Claim 4
Dependent Claim
46 words
A nondispersive gas analyzing apparatus as recited in claim 2 wherein said means forming a first chamber includes a bellows portion, and said means for periodically varying the volume of said first chamber includes an oscillatory means for driving said bellows portion at said first frequency.
Claim 5
Dependent Claim
43 words
A nondispersive gas analyzing apparatus as recited in claim 1 wherein said first modulation means includes means for periodically varying the density of said reference gas and said second modulation means includes a means for periodically varying the density of said unknown gas.
Claim 6
Dependent Claim
52 words
A nondispersive gas analyzing apparatus as recited in claim 4 wherein said means forming said second chamber includes an electrodynamically driven flexible wall member, and said means for periodically varying the density of said unknown gas includes a source of oscillatory electrical energy for driving said wall member at said second frequency.
Claim 7
Dependent Claim
60 words
A nondispersive gas analyzing apparatus as recited in claim 1 wherein said first modulation means includes means for varying the length of the path taken by said radiant energy in passing through said reference gas and said second modulation means includes means for varying the length of the path taken by said radiant energy in passing through said unknown gas.
Claim 8
Dependent Claim
90 words
A nondispersive gas analyzing apparatus as recited in claim 6 wherein said means for varying the path length taken by said radiant energy in passing through said reference gas includes a first reflective surface disposed at an angle relative to the incident radiant energy, and a second reflective surface disposed parallel to said first reflective surface, whereby said radiant energy is reflected from said first reflective surface to said second reflective surface, and means for periodically moving one of said reflective surfaces relative to the other at said first frequency.
Claim 9
Dependent Claim
53 words
A nondispersive gas analyzing apparatus as recited in claim 1 and further comprising chopper means disposed on each side of said first chamber and operative to periodically admit direct radiant energy from said radiant energy source means to enter said first chamber while preventing such direct radiant energy froM entering said second chamber.
Claim 10
Dependent Claim
42 words
A nondispersive gas analyzing apparatus as recited in claim 1 wherein said radiant energy source means includes means forming a third chamber for containing a known gas, and means for causing said known gas to fluoresce and thereby provide said radiant energy.
Claim 11
Dependent Claim
36 words
A nondispersive gas analyzing apparatus as recited in claim 1 wherein said radiant energy source means includes means for causing said reference gas to fluoresce, such fluorescence providing radiant energy for passage through said second chamber.
Claim 12
Dependent Claim
126 words
A gas analyzing method comprising the steps of: providing a quantity of a reference gas and quantity of an unknown gas; directing radiant energy serially through said reference gas and said unknown gas in such a manner that said radiant energy is at least partially absorbed in passing therethrough; modulating the absorption of said radiant energy in said reference gas at a second frequency; modulating the absorption of said radiant energy in said unknown gas at a second frequency; detecting the modulated radiant energy and developing an electrical signal commensurate therewith, said electrical signal including signal components related to the constituents of said unknown gas; and separating from said electrical signal a signal component representative of the quantity of said reference gas in said unknown gas.
Claim 13
Dependent Claim
126 words
A gas analyzing method comprising the steps of: providing a quantity of a reference gas and quantity of an unknown gas; directing radiant energy serially through said reference gas and said unknown gas in such a manner that said radiant energy is at least partially absorbed in passing therethrough; modulating the absorption of said radiant energy in said reference gas at a second frequency; modulating the absorption of said radiant energy in said unknown gas at a second frequency; detecting the modulated radiant energy and developing an electrical signal commensurate therewith, said electrical signal including signal components related to the constituents of said unknown gas; and separating from said electrical signal a signal component representative of the quantity of said reference gas in said unknown gas.
Claim 14
Dependent Claim
62 words
A gas analyzing method as recited in claim 11 wherein the modulation of the absorption of said radiant energy in said reference gas is effected by varying the density of said reference gas at said first frequency, and the modulation of said radiant energy and said unknown gas is effected by varying the density of said unknown gas at said second frequency.
Claim 15
Dependent Claim
84 words
A gas analyzing method as recited in claim 11 wherein the modulation of the absorption of said radiant energy in said reference gas is effected by periodically varying at said first frequency the length of the path taken by said radiant energy in passing through said reference gas, and the modulation of said radiant energy in said unknown gas is effected by periodically varying at said second frequency the length of the path taken by said radiant energy in passing through said unknown gas.
References Cited (Backward Citations)
US2951938A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |