Patent US3666362A successfully refreshed from Google Patents.
US3666362A
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Dual wavelength spectrophotometry
Assignee: JOHNSON RESEARCH FOUNDATION ME
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Filing: 1970-12-22
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Granted: 1972-05-30
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Expires: 1990-12-22
Abstract
Abstract A DUAL WAVELENGTH SPECTROPHOTOMETER IN WHICH COMPENSATION IS MADE FOR LAMP NOISE BY EXTRACING A PORTION OF THE TIME-SHARED DUAL WAVELENGTH LIGHT BEAM BEFORE IT ENTERS THE SAMPLE AND GENERATING A COMPENSATION SIGNAL THEREWITH IN AN AUXILIARY PHTOMMULTIPLIER. THE COMPENSATION SIGNAL IS NORMALIZED AND SUBSTRACTED FROM THE MEASURE SIGNAL IN A DIFFERENTAL AMPLIFIER OVER A BAND WIDTH INCLUDING FREQUENCIES CONSIDERABLY ABOVE THE LIGHT SWITCH FREQUENCY.
Inventors
- 👤 Britton Chance
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:37
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/42; G01J3/427
Claims Analysis
Total Claims: 0
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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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |