Patent US4576486A successfully refreshed from Google Patents.
US4576486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fiber thermometer
Assignee: United States Department of Commerce
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Filing: 1983-08-23
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Granted: 1986-03-18
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Expires: 2003-08-23
Abstract
Abstract A temperature measuring device suitable for high temperature measurements in the range of 500 DEG -2400 DEG C. utilizing a blackbody cavity to emit radiation in the wavelength band of 0.3 mu m-1.0 mu m. The emitted light is transmitted to a photodetector via a high temperature ceramic fiber which is transparent to the wavelength band radiated. The radiance of the cavity is utilized as a measure of its temperature.
Inventors
- 👤 Ray R. Dils
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:28
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/02; G01J5/08; G01J5/0801; G01J5/0802; G01J5/0818; G01J5/0821; G01J5/0846; G01J5/0887; G01J5/04; G01J5/041; G01J5/042; G01J5/048
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
239 words
A temperature measuring device comprising: (a) an elongated high temperature optical fiber, (b) one end of said high temperature fiber having an optically dense film covering the outer surface thereof, thereby defining a region of the covered end of said fiber exhibiting blackbody radiation behavior, said blackbody region and said high temperature fiber able to measure temperatures in the range of 500°-2400° C., said blackbody region having a length to diameter ratio in the range 1/1 to 20/1, (c) said blackbody region emitting radiation primarily in the range of 0.3 μm-1.0 μm within said temperature range of 500°-2400° C., (d) said high temperature fiber having a diameter in the range of 0.025 mm to 2.5 mm and transmitting radiation in said temperature range without substantial absorption thereof, (e) a low temperature fiber having a different diameter than said high temperature fiber and coupled to the other end of said high temperature fiber, (f) a light detector coupled to receive light transmitted by said low temperature fiber and including a narrow-band filter for selecting a narrow optical band wherein relatively small changes in temperature within said band result in relatively large changes in intensity emitted by said blackbody region, said narrow optical band within said 0.3 μm-1.0 μm range, said light detector providing an output signal proportional to the intensity of said received light, and (g) means responsive to said output signal for providing an indication of said temperature measurement.
Claim 2
Dependent Claim
239 words
A temperature measuring device comprising: (a) an elongated high temperature optical fiber, (b) one end of said high temperature fiber having an optically dense film covering the outer surface thereof, thereby defining a region of the covered end of said fiber exhibiting blackbody radiation behavior, said blackbody region and said high temperature fiber able to measure temperatures in the range of 500°-2400° C., said blackbody region having a length to diameter ratio in the range 1/1 to 20/1, (c) said blackbody region emitting radiation primarily in the range of 0.3 μm-1.0 μm within said temperature range of 500°-2400° C., (d) said high temperature fiber having a diameter in the range of 0.025 mm to 2.5 mm and transmitting radiation in said temperature range without substantial absorption thereof, (e) a low temperature fiber having a different diameter than said high temperature fiber and coupled to the other end of said high temperature fiber, (f) a light detector coupled to receive light transmitted by said low temperature fiber and including a narrow-band filter for selecting a narrow optical band wherein relatively small changes in temperature within said band result in relatively large changes in intensity emitted by said blackbody region, said narrow optical band within said 0.3 μm-1.0 μm range, said light detector providing an output signal proportional to the intensity of said received light, and (g) means responsive to said output signal for providing an indication of said temperature measurement.
Claim 3
Dependent Claim
31 words
A temperature measuring device as recited in claim 1 wherein said blackbody region has a surface inclined in the range of 20°-70° from the longitudinal axis of said high temperature fiber.
Claim 4
Dependent Claim
19 words
A temperature measuring device as recited in claim 1 further comprising a protective layer overlaying said optically dense film.
Claim 5
Dependent Claim
16 words
A temperature measuring device as recited in claim 1 wherein said film comprises a noble metal.
Claim 6
Dependent Claim
22 words
A temperature measuring device as recited in claim 4 wherein said noble metal is selected from the group of platinum and iridium.
Claim 7
Dependent Claim
32 words
A temperature measuring device as recited in claim 5 wherein said high temperature fiber is a sapphire fiber and said device further comprises an alumina protective film overlaying said optically dense film.
Claim 8
Dependent Claim
24 words
A temperature measuring device as recited in claim 6 wherein said optically dense film has a thickness on the order of 0.2 μm-10 μm.
Claim 9
Dependent Claim
32 words
A temperature measuring device as recited in claim 5 wherein said high temperature fiber is a zirconia fiber and said device further comprises a zirconia protective film overlaying said optically dense film.
Claim 10
Dependent Claim
24 words
A temperature measuring device as recited in claim 8 wherein said optically dense film has a thickness on the order of 0.2 μm-10 μm.
Claim 11
Dependent Claim
21 words
A temperature measuring device as recited in claim 1 wherein said optically dense film comprises a chemically doped metallic oxide film.
Claim 12
Dependent Claim
23 words
A temperature measuring device as recited in claim 10 wherein said chemically doped metallic oxide film is chromium doped single crystal aluminum oxide.
Claim 13
Dependent Claim
25 words
A temperature measuring device as recited in claim 1 wherein said low temperature fiber is coupled to said high temperature fiber via an air gap.
Claim 14
Dependent Claim
227 words
A temperature measuring device comprising: (a) an elongated high temperature optical fiber, (b) a blackbody region positioned at one end of said high temperature fiber and comprising an optically dense solid oxide material, said blackbody region and said high temperature fiber able to measure temperatures in the range of 500°-2400° C. said blackbody region having a length to diameter ratio in the range 1/1 to 20/1, (c) said blackbody region emitting radation primarily in the range of 0.3 μm-1.0 μm within said temperature range of 500°-2400° C., (d) said high temperature fiber having a diameter in the range of 0.025 mm to 2.5 mm and transmitting radiation in said temperature range without substantial absorption thereof, (e) a low temperature fiber having a different diameter than said high temperature fiber and coupled to the other end of said high temperature fiber, (f) a light detector coupled to receive light transmitted by said low temperature fiber and including a narrow-band filter for selecting a narrow optical band wherein relatively small changes in temperature within said band result in relatively large changes in intensity emitted by said black-body region, said narrow optical band within said 0.3 μm-1.0 μm range, said light detector providing an output signal proportional to the intensity of said received light, and (g) means responsive to said output signal for providing an indication of said temperature measurement.
Claim 15
Dependent Claim
227 words
A temperature measuring device comprising: (a) an elongated high temperature optical fiber, (b) a blackbody region positioned at one end of said high temperature fiber and comprising an optically dense solid oxide material, said blackbody region and said high temperature fiber able to measure temperatures in the range of 500°-2400° C. said blackbody region having a length to diameter ratio in the range 1/1 to 20/1, (c) said blackbody region emitting radation primarily in the range of 0.3 μm-1.0 μm within said temperature range of 500°-2400° C., (d) said high temperature fiber having a diameter in the range of 0.025 mm to 2.5 mm and transmitting radiation in said temperature range without substantial absorption thereof, (e) a low temperature fiber having a different diameter than said high temperature fiber and coupled to the other end of said high temperature fiber, (f) a light detector coupled to receive light transmitted by said low temperature fiber and including a narrow-band filter for selecting a narrow optical band wherein relatively small changes in temperature within said band result in relatively large changes in intensity emitted by said black-body region, said narrow optical band within said 0.3 μm-1.0 μm range, said light detector providing an output signal proportional to the intensity of said received light, and (g) means responsive to said output signal for providing an indication of said temperature measurement.
Claim 16
Dependent Claim
20 words
A temperature measuring device as recited in claim 13 wherein said solid oxide material is aluminum oxide doped with chromium.
Claim 17
Dependent Claim
21 words
A temperature measuring device as recited in claim 14 wherein said chromium is doped in the amount between 0.1-20% by weight.
Claim 18
Dependent Claim
36 words
A temperature measuring device as recited in claim 14 wherein said high temperature fiber is a sapphire fiber and said device further comprises an alumina protective film overlaying said optically dense aluminum oxide doped with chromium.
Claim 19
Dependent Claim
36 words
A temperature measuring device as recited in claim 14 wherein said high temperature fiber is a zirconia fiber and said device further comprises a zirconia protective film overlaying said optically dense aluminum oxide doped with chromium.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-03-17 | 1989-09-16 | 1990-03-18 | $2000.00 | Window Closed / Lapsed |
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