Boiarski, A. A. 1993.
Distributed Fiber Optic Temperature Sensing.
Applications of Fiber Optic Sensors in Engineering Mechanics, F. Ansari, ed., ASCE, New York, pp. 210-224.
(posted August 30, 1996)

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A special fiber optic sensor can measure local temperatures within structures, material processes, and mechanical systems using a distributed sensing format. Several one-kilometer lengths of prototype fiber were produced by modifying the cladding material coated on standard core glasses. Changes in Rayleigh backscattered light from the fiber cladding indicated changes in local temperature at points along the entire fiber length. A demonstration system was assembled consisting of twenty meters of fiber and a special high-resolution Optical Time Domain Reflectometer (OTDR). Data obtained under controlled conditions showed that ten-centimeter long hot spots were detected to within +/- 5 degrees-C accuracy over a 0-150 degrees-C temperature range. In addition, field test results located hot spots in a switchgear circuit breaker at an operating plant.