采用 BOTDR 光纤传感技术的电缆内部温度在线测量研究

摘要

为实现光纤复合电缆内部温度的在线测量，利用电缆内部通信用单模光纤中的自发布里渊散射构建了布里渊光时域反射传感系统（BOTDR）。基于该系统，通过提取单模光纤每个空间分辨率范围内的中心频率，得到光纤沿线的布里渊频移分布，即可计算得到光纤沿线的温度分布。与热电偶单点测量结果相比，二者温度差别小于2℃，而该方法更适用于长距离复合电缆的温度测量。%To on-line monitor the temperature distribution of the fiber compounded cable,the spontaneous Bril-louin scattering of single-mode fiber was applied to construct a Brillouin optical time domain reflectometry (BOTDR).With the BOTDR sensing system,the central frequency of every spatial resolution wasabstracted;then the Brillouin frequency distribution along the sensing fiber was obtained;finally the temperature distribu-tion along the fiber was calculated.Compared to the experimental results of thermo-pairs,the temperature difference was less than 2 ℃;but the BOTDR sensing system was a better scheme for temperature monitoring of long-distance compounded cable.