光纤分布式测温系统中基于迭代法的高准确度温度解调算法

提出了一种利用喇曼散射原理的光纤分布式测温系统中基于迭代的高准确度温度解调算法.针对于常规的反斯托克斯-斯托克斯双光路比值的温度解调算法,该迭代算法进一步校正了光纤中双光路衰减系数差对温度敏感带来的温度测量误差,尤其适用于中距离且温度场复杂的测温环境,实现了高准确度的温度测量.通过理论分析确定了该迭代法的迭代格式,测量了相应的光纤参量,并在传感样机上编写相应的代码通过实验予以验证,在0～90℃温度范围,5km测量长度输出的测温曲线符合预期的测温效果.

High Precision Temperature Calculation Method of Fiber-optic Distributed Temperature Sensing System Based on Iteration Technique

A high precision temperature calculation method of fiber optic distributed temperature sensing system based on iteration technique is introduced. Compared with the traditional calculation methods, this iteration based method further corrects the attenuation coefficient difference of the Raman anti stokes wavelength and stokes wavelength in optical fiber which is temperature sensitive, thus increases the precision of temperature measurement. It especially works well with the measurements of normal distance, complex temperature distribution fields. The iterative formula is established by theoretical analysis, the corresponding fiber parameters are pre measured, by programming on data processing module of the sensing system. The result shows great accordance between calculation and actual temperature distribution within the range from 0 to 90℃ along a whole fiber of 5 km.