研究了一种基于管式弹性应变敏感元件的光纤光栅传感器结构。利用双光纤布拉格光栅(FBG)产生双反射峰,对压力和温度进行了同时区分测量。在压力为0～20 MPa、温度为20～150 ℃的范围内,布拉格反射波长对应压力与温度的变化均呈现良好的线性响应特性,响应灵敏度分别为0.089 nm/MPa和0.024 nm/℃。压力与温度双参量系数矩阵的实验拟合值与理论计算值之差仅占理论计算值的1.8%。该方法与标准测量方法比较,压力的准确度为0.47%;温度的准确度为0.74%。该方法还较好地削减了压力与温度交叉敏感的影响,按压力与温度测量的最大量限计算,温度对压力交叉影响的误差仅为0.16%。

A new structure of fiber Bragg grating (FBG) sensor based on sticking two FBGs on tubular elastic element is developed. Simultaneous measurement for the pressure and temperature has been experimented by two FBGs producing two wave spike respectively. In the range of 0～20 MPa and 20～150 ℃, the FBG's Bragg wavelength change is linear to the pressure and temperature. The pressure and temperature sensitivities are 0.089 nm/MPa and 0.024 nm/℃ respectively. The experimental value of coefficient matrix of the FBG's wavelength change to pressure and temperature is coincidented with the theoretical value very well, and the relative error is 1.8%. Compared with the standard measurement method, and the accuracies of pressure and temperature are 0.47% and 0.74% respectively. The method can cut the error arising from the temperature cross-sensitivity in pressure, the error of which is about 0.16% as pressure and temperature are at 20 MPa and 150 ℃ respectively.