Temperature corrected strain measurements using optical time domain reflectometry

A method of using optical fiber to measure strain and correct for the effects of temperature is proposed. A means of measuring apparent strain is given, pure temperature is measured using Fresnel-backscatter based Optical Time Domain Reflectometry, and a method for combining the two measurements to obtain a measurement of mechanically-induced strain alone is developed. The background, theory and experimental results that demonstrate the feasibility of such a system are presented and the results are compared with the performance of existing fiber-based means of measuring temperature. Experiments on several OTDR-addressed, intensity-based optical temperature sensors are performed and a method for manufacturing small air gap splices for use in measuring strain at several places along an optical fiber are presented.