一种应力迟滞和温度自动补偿型FBG压力传感器

FBG sensor of measuring pressure with lag of stress active compensation and with temperature active compensation

基于波登管与悬臂梁的组合设计,将2个相同波长的光纤布拉格光栅(FBG)分别与悬臂梁的上、下表面对称粘贴组成差动式FBG传感系统,实现了外压力调谐双FBG布拉格波长差的调谐方法。理论分析和实验研究结果表明,该系统不仅能自动补偿FBG压力传感系统中弹性衬底元件在加压和减压过程中的弹性迟滞,而且能同时自动补偿温度,改善传感系统的线性响应特性;在0～20MPa的压力范围内,双峰波长差的调谐范围为0.0～5.6nm,压力调谐双峰波长差的灵敏度可达0.28nm/MPa,是压力调谐单峰波长灵敏度的2倍,标准误差可由单峰的0.066nm降低到0.0084nm。

Adopting the design of the structure combining Bourdon tube with cantilever beam with two FBG which have same wavelengths and are symmetry affixed on the cover surface and the bottom surface of cantilever beam respectively,the tuned method of the pressure tune two FBG＇s Bragg wavelength difference is realized. The theoretical analysis and experimental results show that the sensor has the function of the elasticity lag and aftereffect active compensation with temperature active compensation, and two-FBG＇s Bragg wavelength difference is linear to the pressure,in the range of 0-20 MPa, the maximal wavelength difference of 5.6 nm can be gotten. The sensitivities of the pressure tune two FBG＇s Bragg wavelength difference is 0.28 nm/MPa,which is about 2 times the value of the pressure tune single FBG＇s Bragg wavelength. The standard errors of are reduce from 0. 066 nm of single FBG to 0. 0084 nm of two-FBG＇s.