基于双光纤光栅温度压力同时区分测量的研究

Study on simultaneous discriminating measurement of temperature and pressure based on dual FBG

提出了一种基于薄壁圆柱壳体的压力温度同时区分测量的光纤Bragg光栅(FBG)传感器结构。将双FBG沿着轴向分别粘贴在壁厚度不均匀的柱体外表面,由于两个FBG受到温度影响而引起的波长漂移量是相同的,这时两光栅Bragg波长漂移量之差就完全取决于压力,从而实现对压力温度的区分测量。实验测得,在0～7MPa内传感器的压力响应灵敏度为0.073nm/MPa,在22.6～112.6℃内的温度灵敏度为0.037nm/℃,分别是裸FBG的24倍和3.7倍。结果也表明,这种传感器具有良好的线性度与可重复性。

Based on the thin-wall cylindrical shell,a new fiber Bragg grating（FBG） sensor to measure the temperature and the pressure simultaneously is proposed by using dual FBGs.Two gratings are stuck to the outer surface of the cylindrical shell with nonuniform thickness along the axial direction.The gratings have similar temperature responses but different strain responses,so the simultaneous measurement can be realized.The experimental results show that the pressure sensitivity coefficient and temperature sensitivity coefficient are 0.073 nm/MPa and 0.037 nm/℃ respectively,which are 24 and 3.7 times of that of bare FBG,within the range of 0-7 MPa and 22.6-112.6 ℃.The results also indicate that this sensor has a good linear response and repeatability.