对传统的应变标定方法进行了分析, 发现其不适用于无封装光纤布拉格光栅(FBG)传感器的应变标定。提出了一种简易的无封装FBG传感器的应变灵敏度系数标定方法, 通过理论分析, 证明了该方法的可行性。选取能够覆盖解调仪解调范围的不同中心波长的无封装FBG传感器进行标定实验。计算了实验的A类不确定度、FBG传感器的线性度, 并分析了标定结果与理论值存在差异的原因。实验结果表明, 提出的方法在四支FBG传感器上均取得了3×10-3pm/με以下的A类不确定度和0.5%以下的线性度。

Based on analyzing traditional calibration methods, it is found that they are not suitable for the calibration of unencapsulated FBG sensors. Thus a simple calibration method of strain sensitivity coefficient for unencapsulated FBG sensor was proposed. Experiments were carried out to calibrate the unencapsulated FBG sensor with different central wavelength which can cover the demodulation range of demodulator. The type A uncertainty and linearity of FBG sensor were calculated, and the reasons for the difference between calibration result and theoretical value were analyzed. Experimental results show that the proposed method achieves type A uncertainty of less than 3×10-3pm/με and linearity below 0.5% on four FBG sensors.