US3906226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitric oxide pollution monitor
Assignee: United States Department of Commerce
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Filing: 1974-03-29
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Granted: 1975-09-16
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Expires: 1994-03-29
Abstract
Abstract A monitor for NO in a gas stream which comprises a flow-type fluorescence cell, means for flowing a sample stream through the cell, means for irradiating the sample stream with ultraviolet light to cause fluorescence of NO, and means for measuring the fluorescene intensity of NO in the sample stream.
Inventors
- 👤 Hideo Okabe
- 👤 Frederick P Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:09
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/0004; G01N33/0009; G01N33/0027; G01N21/00; G01N21/62; G01N21/63; G01N21/64
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
A FLUORESCENCE METHOF FOR DETERMINING RELATIVELY SMALL CONCENTRATIONS OF NO IN A GASEOUS MIXTURE, SUCH AS AUTOMOTIVE EXHAUST GAS, WHICH CINTAINS RELATIVELY LARGE CONCENTRATIONS OF NO FLUORESCENCE QUENCHING GASES SUCH AS CO2 AND H2O, COMPRISING: IRRADIATING A GAS CONSISTING ESSENTIALLY OF N2 WITH ULTRAVIOLET IN ABOUT THE 2,100-2,300 A REGION AND MEASURING THE RESULTANT BACKGROUND SIGNAL AT ABOUT 2,200-3,200 A, DILUTING SAID GASEOUS MIXTURE WITH N2 IN A VOLUME RATIO OF ABOUT 1:100, IRRADIATING SAID N2-DILUTED GASEOUS MIXTURE WITH ULTRAVIOLET IN ABOUT SAID 2,100-2,300 A REGION AND MEASURING THE RESULTANT BACKGROUND AND NO FLUORESCENCE SIGNAL AT ABOUT SAID 2,200-3,200 A, AND SUBTRACTING SAID BACKGROUND SIGNAL FROM SAID BACKGROUND AND NO FLUORESCENCE SIGNAL TO OBTAIN THE DESIRED NO FLUORESCENCE SIGNAL, SAID DILUTION OF SAID GASEOUS MIXTUR WITH N2 SERVING TO REDUCE FLUCTUATIONS IN SAID NO FLUORESCENCE SIGNAL DUE TO FLUCTUATIONS IN THE CONCENTRATIONS OF SAID NO FLUORESCENCE QUENCHING GASES IN SAID GASEOUS MIXTURE.
Claim 2
Dependent Claim
152 words
A FLUORESCENCE METHOF FOR DETERMINING RELATIVELY SMALL CONCENTRATIONS OF NO IN A GASEOUS MIXTURE, SUCH AS AUTOMOTIVE EXHAUST GAS, WHICH CINTAINS RELATIVELY LARGE CONCENTRATIONS OF NO FLUORESCENCE QUENCHING GASES SUCH AS CO2 AND H2O, COMPRISING: IRRADIATING A GAS CONSISTING ESSENTIALLY OF N2 WITH ULTRAVIOLET IN ABOUT THE 2,100-2,300 A REGION AND MEASURING THE RESULTANT BACKGROUND SIGNAL AT ABOUT 2,200-3,200 A, DILUTING SAID GASEOUS MIXTURE WITH N2 IN A VOLUME RATIO OF ABOUT 1:100, IRRADIATING SAID N2-DILUTED GASEOUS MIXTURE WITH ULTRAVIOLET IN ABOUT SAID 2,100-2,300 A REGION AND MEASURING THE RESULTANT BACKGROUND AND NO FLUORESCENCE SIGNAL AT ABOUT SAID 2,200-3,200 A, AND SUBTRACTING SAID BACKGROUND SIGNAL FROM SAID BACKGROUND AND NO FLUORESCENCE SIGNAL TO OBTAIN THE DESIRED NO FLUORESCENCE SIGNAL, SAID DILUTION OF SAID GASEOUS MIXTUR WITH N2 SERVING TO REDUCE FLUCTUATIONS IN SAID NO FLUORESCENCE SIGNAL DUE TO FLUCTUATIONS IN THE CONCENTRATIONS OF SAID NO FLUORESCENCE QUENCHING GASES IN SAID GASEOUS MIXTURE.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |