US3829696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Atmospheric no monitor
Assignee: Aerospace Corp
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Filing: 1973-04-26
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Granted: 1974-08-13
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Expires: 1993-04-26
Abstract
Abstract Method and apparatus for the continuous, real-time measurement of the nitrogen dioxide (NO2) content of a gaseous atmosphere. A flowing or non-confined atmospheric sample is subjected to energizing radiation in the broad NO2 absorption spectrum, preferably between about 400 and 600 nm., with sufficient energy to excite the NO2 to its fluorescent state. A detector measures the fluorescence in the red band (about 620 nm. to 800 nm.) with lower wavelength radiation, including the exciting radiation, being filtered from the detector. The detector output count provides a direct indication of the NO2 constituent with an accuracy of 1 part per hundred million or better.
Inventors
- 👤 M Birnbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:03
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/64; G01N21/6402
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
110 words
Apparatus for measuring the NO2 content of a gaseous atmosphere comprising: a. means for illuminating and energizing a sample of the atmosphere within the absorption spectrum of NO2, said means having a power range to effect fluorescense of the NO2; b. means for measuring the fluorescent emmission from the NO2 upon energization thereof; c. means for shielding the measuring means from light in a waveband including the wavelength of the illuminating means; d. a NO2 absorbing filter; and, e. means for selectively passing a sample of the atmosphere through the NO2 filter prior to the energization thereof by the illuminating means to provide a null indicator for the measuring means.
Claim 2
Dependent Claim
182 words
Apparatus for measuring the NO2 content of a gaseous atmosphere comprising: a. a walled chamber having an interior sealed off from external ambient light; b. means providing a flow of the gaseous atmosphere through the interior of the chamber; c. a laser providing a monochromatic output beam within a range of the spectrum corresponding to the range of maximum absorbtivity of light by NO2; d. an entrance aperture at one side of the chambeR and an exit aperture at an opposite side of the chamber, said laser output beam passing through the chamber via the entrance and exit apertures; e. light collimating means for confining the laser output beam within the chamber interior whereby only the gas within the chamber is subjected to illumination by the laser beam; f. means measuring fluorescent emissions from the NO2 in the chamber upon excitation by the laser beam travelling through the chamber; g. a red band-pass filter shielding the measuring means from light of shorter wavelength including the laser beam, said filter being substantially non-fluorescent under irradiation by light of the wavelength of the laser.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |