Patent US3924469A successfully refreshed from Google Patents.
US3924469A
Expired / Lapsed
US
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Apparatus for measuring surface temperatures of objects by infrared radiation therefrom
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1974-03-11
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Granted: 1975-12-09
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Expires: 1994-03-11
Abstract
Abstract Apparatus for measuring the temperature at the surface of an object by measurement of the infrared radiation emitted from its surface comprises a variably heated metallic body which serves as a compensating radiator, a reflective member mounted on a shaft within a cavity provided within the compensating radiator body for rotation, or alternatively oscillation, about an axis forming an oblique angle to the plane of the reflective member such that in one position of the reflective member only infrared radiation from the surface of the object is reflected by it into a radiation detector, while in another position of the reflective member only infrared radiation from a wall surface of the cavity within the compensating radiator is reflected by it into the radiation detector, thusly admitting infrared radiation from the object and compensating radiator in alternation to the radiation detector. The detector produces at its output an alternating current signal determined by any temperature differential existing between the object and compensating radiator, and the heat supply to the compensating radiator is varied in accordance with the signal in such sense as to reduce the signal to zero whereby the temperature of the compensating radiator then equals the temperature of the object.
Inventors
- 👤 Gerold Brandli
- 👤 Pierre Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:53
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/52
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
244 words
Apparatus for measuring the temperature at the surface of an object by measurement of infrared radiation emitted from the surface which comprises a compensating radiator in the form of a body having a good thermal conductivity characteristic, a radiation detector, a planar reflective member located within a cavity provided within said compensating radiator, said reflecting member being mounted at its center on a rotatable shaft extending through a bore in said compensating radiator to the exterior thereof for actuation by a motor to effect cyclic rotational movement about an axis forming an oblique angle to the plane of said reflective member between first and second positions such that in one such position only radiation from the surface of the object entering said cavity is reflected by said reflector member into said detector through a second bore in said compensating radiator aligned with said rotatable shaft while in the other such position only radiation from a wall surface of said cavity is reflected by said reflective member into said detector thusly admitting radiation from the object and compensating radiator in alternation to said detector, said detector producing at its output a signal determined in accordance with any radiation differential existing between the object and compensating radiator, and means controlled by said output signal for variably heating said compensating radiator in such sense as to reduce said signal to zero thereby to attain a condition of radiation equilibrium as between the object and said compensating radiator.
Claim 2
Dependent Claim
244 words
Apparatus for measuring the temperature at the surface of an object by measurement of infrared radiation emitted from the surface which comprises a compensating radiator in the form of a body having a good thermal conductivity characteristic, a radiation detector, a planar reflective member located within a cavity provided within said compensating radiator, said reflecting member being mounted at its center on a rotatable shaft extending through a bore in said compensating radiator to the exterior thereof for actuation by a motor to effect cyclic rotational movement about an axis forming an oblique angle to the plane of said reflective member between first and second positions such that in one such position only radiation from the surface of the object entering said cavity is reflected by said reflector member into said detector through a second bore in said compensating radiator aligned with said rotatable shaft while in the other such position only radiation from a wall surface of said cavity is reflected by said reflective member into said detector thusly admitting radiation from the object and compensating radiator in alternation to said detector, said detector producing at its output a signal determined in accordance with any radiation differential existing between the object and compensating radiator, and means controlled by said output signal for variably heating said compensating radiator in such sense as to reduce said signal to zero thereby to attain a condition of radiation equilibrium as between the object and said compensating radiator.
Claim 3
Dependent Claim
39 words
Apparatus as defined in claim 1 for measuring the temperature of an object by radiation emitted from a surface thereof wherein said reflective member rotates continuously in one direction and said first and second positions are located 180* apart.
Claim 4
Dependent Claim
36 words
Apparatus as defined in claim 1 for measuring the temperature of an object by radiation emitted from a surface thereof wherein said reflective member oscillates about its axis of rotation between said first and second positions.
Claim 5
Dependent Claim
37 words
Apparatus as defined in claim 3 for measuring the temperature of an object by radiation emitted from a surface thereof wherein the angle through which said reflective member oscillates lies in a range between 60* and 180*.
Claim 6
Dependent Claim
28 words
Apparatus as defined in claim 1 for measuring the temperature of an object by radiation emitted from a surface thereof wherein said reflective member has an elliptical configuration.
Claim 7
Dependent Claim
45 words
Apparatus as defined in claim 1 for measuring the temperature of an object by radiation emitted from a surface thereof wherein said compensating radiator includes a bore extending from said cavity to the exterior thereof and through which the object is inserted into said cavity.
Claim 8
Dependent Claim
38 words
Apparatus as defined in claim 6 for measuring the temperature of an object by radiation emitted from a surface thereof wherein the bore through which the object is inserted into said cavity extends completely through the compensating radiator.
Claim 9
Dependent Claim
14 words
Apparatus as defined in claim 1 wherein said second bore includes a radiation conductor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |