基于光纤布拉格光栅(FBG)高温传感特性,设计了一种基于波长调制的耐高温光纤光栅传感网络。系统设计了新型封装结构的耐高温光栅传感头。并针对传统FBG传感网络结构可靠性低的缺点,设计了一种高可靠分布式传感网络结构。采用InGaAs图像传感衍射解调技术对光反射波长进行解调。20~290℃范围测试实验表明,所设计的传感网络温度响应曲线平均线性度达0.9991,灵敏度为0.0258nm/℃,测量精度达±0.6℃,响应时间小于16S,稳定性高,适用于实际工作环境中的高温测量。
A high temperature fiber Bragg grating (FBG) sensing network based on wavelength modulation is highly developed on the basis of FBG high temperature sensing characters. A new packaged high temperature FBG sensor head is designed in this system. A high reliable distributed sensing network structure is also proposed to overcome the low reliability of the traditional FBG sensing network. Diffraction technique based on InGaAs image sensing is used to demodulate reflected wavelength. The results show that the average goodness-of-fit of sensing system's temperature curve is 0. 9991, the sensitivity is 0. 0258 nm/℃, the accuracy is±0.6 ℃ and the response time is less than 16 s. Moreover, the sensing network is steady enough for high temperature measurement.