US3840343A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame detector
Assignee: Hewlett Packard GmbH Germany
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Filing: 1972-09-07
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Granted: 1974-10-08
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Expires: 1992-09-07
Abstract
Abstract In a flame detector a gas mixture to be analyzed is supplied to a flame jet and ionized. The signal derived from the ions or photons emanating from the flame are used to identify specific gas components. The signal to noise ratio with this kind of detector may be improved by surrounding the top of the flame nozzle with a annular electrode to which a negative potential relative to the potential of the nozzle is applied. It is supposed that the improved performance results from the absorption of positive carbon containing ions of organic components which otherwise would cause background noise.
Inventors
- 👤 M Riedmann
- 👤 J Vogt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:15
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/62; G01N27/626
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
143 words
A FLAME DETECTOR FOR GAS CHROMATOGRAPH COMPRISING: A HOUSING; A FLAME NOZZLE MOUNTED IN THE HOUSING, THE NIZZLE HAVING AN OPEN END AT WHICH A FLAME MAY BE MAINTAINED; FIRST INLET MEANS FOR DIRECTING A MIXTURE OF A CQARRIER GAS AND A SAMPLE GAS TO THE FLAME NOZZLE; SECOND INLET MEANS FOR SUPPLYING A COMBUSTIBLE GAS TO THE VICINITY OF THE FLAME NOZZLE; A COLLECTOR ELECTRODE MOUNTED IN THE HOUSING APART FROM THE FLAME NOZZLE; ION MEASURING AND BIASING MEANS CONDUCTIVELY CONNECTED BETWEEN THE COLLECTOR ELECTRODE AND FLAME NOZZLE FOR BIASING THE COLLECTOR AT A NEGATIVE POTENTIAL RELATIVE TO THE FLAME NOZZLE; A RING SHAPED ELECTRODE DISPOSED ABOUT AND DIRECTLY ADJACENT TO THE OPEN END OF THE FLAME NOZZLE; AND SECOND BIAS MEANS CONDUCTIVELY CONNECTED TO THE RING ELECTRODE FOR BIASING THE RING ELECTRODE AT A NEGATIVE POTENTIAL RELATIVE TO THE COLLECTOR ELECTRODE.
Claim 2
Dependent Claim
143 words
A FLAME DETECTOR FOR GAS CHROMATOGRAPH COMPRISING: A HOUSING; A FLAME NOZZLE MOUNTED IN THE HOUSING, THE NIZZLE HAVING AN OPEN END AT WHICH A FLAME MAY BE MAINTAINED; FIRST INLET MEANS FOR DIRECTING A MIXTURE OF A CQARRIER GAS AND A SAMPLE GAS TO THE FLAME NOZZLE; SECOND INLET MEANS FOR SUPPLYING A COMBUSTIBLE GAS TO THE VICINITY OF THE FLAME NOZZLE; A COLLECTOR ELECTRODE MOUNTED IN THE HOUSING APART FROM THE FLAME NOZZLE; ION MEASURING AND BIASING MEANS CONDUCTIVELY CONNECTED BETWEEN THE COLLECTOR ELECTRODE AND FLAME NOZZLE FOR BIASING THE COLLECTOR AT A NEGATIVE POTENTIAL RELATIVE TO THE FLAME NOZZLE; A RING SHAPED ELECTRODE DISPOSED ABOUT AND DIRECTLY ADJACENT TO THE OPEN END OF THE FLAME NOZZLE; AND SECOND BIAS MEANS CONDUCTIVELY CONNECTED TO THE RING ELECTRODE FOR BIASING THE RING ELECTRODE AT A NEGATIVE POTENTIAL RELATIVE TO THE COLLECTOR ELECTRODE.
Claim 3
Dependent Claim
22 words
A flame detector as in claim 1 wherein a piece of salt is disposed between the flame nozzle and the collector electrode.
Claim 4
Dependent Claim
28 words
A flame detector as in claim 1 further including overpressure means for maintaing the interior of the housing at a pressure greater than the exterior of the housing.
Claim 5
Dependent Claim
53 words
A flame detector as in claim 3 wherein the overpressure means includes an opening in the housing separated from a portion of the volume of the housing by a grid for maintaining said portion of the housing at a pressure greater than the remainder of the housing and the exterior of the housing.
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) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |