光纤多参数传感器研究

Study on optical fiber multi-parameter sensor

基于光纤Bragg光栅(FBG)检测原理,研发了适用于地下空间安全监测应用的光纤风速、温度、湿度等多参数传感器。光纤风速传感器基于激光致热光纤热线式流量检测原理,对于低风速有较高的灵敏度,风速从0变化到0.5 m/s时,FBG波长变化量为800 pm,采用解调精度为1 pm的光纤光栅解调仪,风速分辨率为0.7 mm/s。光纤湿度传感器通过在FBG光栅表面均匀涂覆湿度敏感的聚酰亚胺溶液,湿度变化导致光纤应变变化进而实现湿度测量。对新型光纤光栅温湿度传感器的性能参数进行测试,实验测试结果显示,传感器监测灵敏度为4.2pm/%RH,检测精度小于±3%RH。

Based on the principle of fiber Bragg grating detection, an optical fiber sensor for detecting wind speed and temperature and humidity in underground space was designed. The designed optical fiber wind speed sensor was based on the thermal flow detection method, which has high sensitivity to low wind speed. For the speed rising from 0 to 0.5 m/s, the wavelength variation is about 800 pm. For the demodulator with sensitivity of 1 pm, the speed resolution is 0.7 mm/s. Fiber optic humidity sensor was fabricated by uniform surface coating of FBG element in polyimide solution, and detection sensitivity of 4.2 pm/% RH was achieved with accuracy less than ± 3% RH.