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US 4,576,486 AGranted
Optical fiber thermometer
AssigneeThe United States of America as represented by the Secretary of Commerce
InventorRay R. Dils
Life of this patent
Estimating the term…
Abstract
A temperature measuring device suitable for high temperature measurements in the range of 500.degree.-2400.degree. 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.
Claims17
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.degree.-2400.degree. 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 .mu.m-1.0 .mu.m within said temperature range of 500.degree.-2400.degree. 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 .mu.m-1.0 .mu.m 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.
4 more elements
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.degree.-2400.degree. 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 .mu.m-1.0 .mu.m within said temperature range of 500.degree.-2400.degree. 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 .mu.m-1.0 .mu.m 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.
4 more elements
Dependencies are inferred from the claim text.