光纤布拉格光栅压力传感器标定中的不确定度研究

Study on Uncertainty of FBG Pressure Transducer Calibration

研制了一种量程为10k N的光纤布拉格光栅压力传感器标定装置,可实现光纤布拉格光栅压力传感器的标定和静态测试。对光纤光栅解调仪获得的中心波长和标准测力仪的压力值进行最小二乘拟合,求出静态标定系数,并分析了标定装置的不确定度来源以合成不确定度。试验结果表明:光纤布拉格光栅压力传感器的响应灵敏度为9.77×10^(-5)nm/N,线性度2.79%FS,经二阶拟合后重复性误差2.61%FS,标定装置的A类不确定度5.73N。

A calibration equipment with lOkN range for FBG （fiber bragg grating） pressure sensor was devel-oped to realize calibration and static testing of the FBG pressure sensor. Through having central wavelength ob- tained by fiber grating demodulation and the standard dynamometer＇ s pressure value prepared for the least squares fitting, and the static calibration coefficient was obtained and the uncertainty＇ s sources of calibration device was analyzed to compound the uncertainty. The experimental results show that, the FBG pressure sen- sor＇s sensitivity stays at 9.77 ×10^-5nm/N with 2.79% FS for the linearity; and the repeatability error is 2.61% FS after second-order fitting and the class A uncertainty of the calibration device is 5.73N.