US3794838A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compensation means for ambient temperature changes of a radiation chopper in a radiometer
Assignee: Barnes Engineering Co
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Filing: 1972-02-10
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Granted: 1974-02-26
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Expires: 1992-02-10
Abstract
Abstract A radiometer is provided with optics, a reference black body cavity, a radiation detector located at the apex of the black body cavity, a radiation chopper external to the black body cavity having alternate mirrored and open segments, and conventional electronic processing circuitry for receiving and processing an output signal from the radiation detector. A blackened vane is positioned in close proximity to the chopper for tracking the temperature of the radiation chopper, and extends into the field of view of the radiometer on the occurrence of an open sector of the chopper, with the area of the vane which extends into the field of view of the radiometer being equal to the clear aperture area of the optical means times the emissivity of the radiation chopper, which provides compensation for changes in the radiation chopper temperature.
Inventors
- 👤 M Weiss
- 👤 R Buckley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:26
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/08; G01J5/0803; G01J5/0805
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
160 words
A radiometer which compensates for changes in radiation chopper temperature comprising a. a radiation detector, b. a radiation reference source, c. optical means for applying radiation from the field of view of said radiometer to said radiation detector, d. radiation chopping means having alternate reflective opaque and transparent sectors for alternately passing radiation from said field of view through said transparent sector and radiation from said reference source to said radiation detector when said opaque sector blocks said field of view, and e. adjustable and lockable compensation means Stationary in their locked position, said means being positioned in close proximity to and in substantially the same temperature environment as the said radiation chopping means which is positioned with respect to said radiation chopping means such that it is in the field of view of said radiometer on the occurrence of each said transparent sector and blocked therefrom on the occurrence of each said opaque sector of said radiation chopping means.
Claim 2
Dependent Claim
160 words
A radiometer which compensates for changes in radiation chopper temperature comprising a. a radiation detector, b. a radiation reference source, c. optical means for applying radiation from the field of view of said radiometer to said radiation detector, d. radiation chopping means having alternate reflective opaque and transparent sectors for alternately passing radiation from said field of view through said transparent sector and radiation from said reference source to said radiation detector when said opaque sector blocks said field of view, and e. adjustable and lockable compensation means Stationary in their locked position, said means being positioned in close proximity to and in substantially the same temperature environment as the said radiation chopping means which is positioned with respect to said radiation chopping means such that it is in the field of view of said radiometer on the occurrence of each said transparent sector and blocked therefrom on the occurrence of each said opaque sector of said radiation chopping means.
Claim 3
Dependent Claim
15 words
The radiometer set forth in claim 1 wherein said compensation means is a blackened vane.
Claim 4
Dependent Claim
51 words
The radiometer set forth in claim 2 wherein the area of said vane in its adjusted and locked position is located in the field of view of said optical means and equals the area covered by the entrance pupil of said optical means times the emissivity of said radiation chopping means.
Claim 5
Dependent Claim
52 words
The radiometer set forth in claim 2 wherein said radiation reference source is a temperature controlled cavity, said radiation detector means being positioned at the apex of said cavity and said optical means being positioned within said cavity opposite said detector means, and said radiation chopping means being positioned outside said cavity.
Claim 6
Dependent Claim
43 words
The radiometer set forth in claim 4 wherein the area of said vane located in the field of view of said optical means equals the area covered by the entrance pupil of said optical means times the emissivity of said radiation chopping means.
References Cited (Backward Citations)
US3392282A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |