用于超导导体测试的FBG应变传感器标定研究

Calibration of FBG strain transducers for superconductors testing

本文提出了一种适用于超导导体测试需求的FBG应变传感器不同温度下的标定方法,将FBG应变传感器采用低温胶水加压固化的方法紧密粘贴于棒状拉伸试样所开设的V型槽内,利用拉力试验机进行台阶式加载标定实验研究,通过中心波长和应变进行拟合,标定得出的FBG应变传感器的应变灵敏度系数。实验测得在室温、液氮、液氦三种温度下应变灵敏度系数分别约为1.1998、1.2031和1.1204,发现FBG应变传感器在固定温度下,波长偏移量与应变呈现线性关系,液氦温度下的应变灵敏度系数小于室温与液氮温度下的应变灵敏度系数。

In this paper,a calibration method for FBG strain sensors at different temperatures applicable to conductor testing needs was proposed.The FBG strain sensor was tightly pasted into the V-groove opened by the rod-shaped tensile specimen using low-temperature glue cured under pressure,and the experimental study of step loading calibration was carried out by using a tensile testing machine,and the strain sensitivity coefficients of the FBG strain sensors derived from the calibration were fitted by the centre wavelength and the strain.The strain sensitivity coefficients at room temperature,liquid nitrogen,and liquid helium were measured to be about 1.1998,1.2031,and 1.1204,respectively.It is found that the wavelength offset of the FBG strain sensors shows a linear relationship with the strain at a fixed temperature,and the strain sensitivity coefficients at the temperature of liquid helium are smaller than those at the temperatures of room temperature and liquid nitrogen.