差分法在FBG测温系统中的应用

Application of difference method in FBG temperature measurement system

为了提高系统的稳定性和抗干扰能力,将差分法应用于光纤Bragg光栅（FBG）测温系统中。给出了相应的理论计算,列出了差分补偿算法的步骤。实验针对25.0~75.0℃的温度测试范围进行检测,结果显示,回波信号对应的中心波长与温差的变化关系基本符合：每1.0℃得到0.04 nm的偏移。采用差分型测温系统的系统误差低于0.5%,比单FBG的精度高4倍左右。具有更好的稳定性与抗干扰能力。

In order to improve stability and anti-jamming capability of system,differential method is applied to FBG temperature measurement system. The corresponding theoretical calculation is given,list steps of differential compensation algorithm. Experimental test temperature range 25. 0~ 75. 0 ℃,the results show that the relationship between changes in echo signal corresponding to temperature difference between center wavelength of the fundamental accord that each 1. 0 ℃ get 0. 04 nm shift. System error of differential temperature measurement system type is less than 0. 5 %,precision is about 4 times higher than single FBG. Thus,temperature measurement system based on differential has better stability and anti-jamming capability.