Patent US4415264A successfully refreshed from Google Patents.
US4415264A
Expired / Lapsed
US
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Spectrophotometer gas control system
Assignee: Applied Biosystems Inc
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Filing: 1981-06-25
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Granted: 1983-11-15
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Expires: 2001-06-25
Abstract
Abstract This invention relates to a spectrophotometer which includes a burner adapted for burning a gaseous fuel and for atomizing a sample to be analyzed in a burner compartment, mechanical elements or electrical circuitry serving to periodically pass a beam of light through the burner compartment, a detector, electrical circuitry for energizing the detector during the period of absence of the beam of light through the burner compartment, said detector being adapted when energized to produce an electronic signal representative of the presence of a flame in the burner compartment; and control elements responsive to the electronic signal for controlling the feeding of fuel to the burner.
Inventors
- 👤 Charles M. Wittmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:07
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/71; G01N21/72; F; F23; F23N; F23N5/00; F23N5/02; F23N5/08; F23N5/082; F23N2241/00; F23N2241/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
97 words
A spectrophotometer comprising, in combination: a burner for burning a gaseous fuel and for atomizing a sample to be analyzed in a burner compartment; means for periodically passing a beam of light through the burner compartment; a detector; means for energizing said detector during the period of absence of said beam of light through said burner compartment; said detector being adapted when energized to produce an electronic signal representative of the presence or absence of a flame in said burner; and means responsive to said electronic signal, for controlling the feeding of the fuel to said burner.
Claim 2
Dependent Claim
97 words
A spectrophotometer comprising, in combination: a burner for burning a gaseous fuel and for atomizing a sample to be analyzed in a burner compartment; means for periodically passing a beam of light through the burner compartment; a detector; means for energizing said detector during the period of absence of said beam of light through said burner compartment; said detector being adapted when energized to produce an electronic signal representative of the presence or absence of a flame in said burner; and means responsive to said electronic signal, for controlling the feeding of the fuel to said burner.
Claim 3
Dependent Claim
39 words
A spectrophotometer according to claim 1, wherein said means responsive to said electronic signal for controlling the feeding of fuel to said burner include switching means having a constant time delay network responsive to the output of said detector.
Claim 4
Dependent Claim
68 words
A spectrophotometer according to claim 2, wherein said switching means having a constant time delay network comprises a transistor having its base connected to the output of said detector and having its collector connected through a resistor to a voltage source and having its emitter connected to a capacitor and a resistor connected in parallel to ground, said emitter being also connected to control means for said burner.
Claim 5
Dependent Claim
26 words
A spectrophotometer according to claim 1 wherein said means for periodically passing a beam of light through the burner compartment comprises a rotary mechanical chopper assembly.
Claim 6
Dependent Claim
54 words
A spectrophotometer according to claim 4 wherein said means for energizing said detector comprises a chopper position sensor, and switching means responsive to said chopper position sensor for directing a source of voltage to said detector for energizing said detector during the period of absence of said beam of light through the burner compartment.
Claim 7
Dependent Claim
17 words
A spectrophotometer according to claim 5 wherein said switching means comprises an electronic switch employing semiconductor elements.
References Cited (Backward Citations)
US3586441A
Cited
US3583844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |