Modeling and Optimization of a Cost-Efficient Distributed Temperature Sensor Based on Temperature Sensitive Optical Fibers

A cost-efficient distributed temperature sensor based on Rayleigh scattering in temperature sensitive optical fibers was proposed. The temperature dependence of the irradiated commercial off-the-shelf single mode fiber was analyzed. By combining a temperature dependent model of the sensitive fibers and loss resolution model of optical time domain reflectometer, a general sensor model has been developed. In order to optimize the temperature resolution, the length of each sensing segment and the overall sensing distance, three models are derived from the general model. Based on the models and parameters optimization, a novel design method is proposed. Using the method, a prototype was built and tested. The test results indicate that the temperature resolution is better than 1 °C in the temperature range from −40 °C to 150 °C, which is consistent with the optimal results.