钳压法制作的同轴电缆法布里-珀罗传感器

Coaxial cable Fabry-Perot sensor fabricated by clamping method

为研究同轴电缆法布里-珀罗干涉(CCFPI)传感器的钳压法制作工艺,模拟不同结构参数对CCFPI传感器信号质量的影响,分析得出CCFPI反射点的绝缘层外径宜在1.4~2 mm范围内,钳压变形长度不应小于2 mm,反射点一致性对信号质量影响显著;模拟电缆拉伸过程,观察到信号频移对电缆应变呈现良好的线性反应。依据模拟结果制作CCFPI传感器,并进行传感性能测试。试验结果表明:CCFPI传感器测得的应变值始终与千分表吻合良好,二者拟合斜率为1.004 92,相关系数为0.998 67,且在小应变范围内CCFPI传感器的测量数据与光纤光栅吻合良好,说明该传感器的测量结果真实可靠;同时观察到CCFPI传感器的分辨率可达110με,失效应变为140 000με。

To investigate the fabrication of CCFPI （coaxial cable Fabry-Perot interferometer） sensor with clamping method, the effects of different structural parameters on the sensing signal quality of CCFPI sensor is simulated. Simulation results show that the outer diameter of the insulation layer of CCFPI reflection point should be between 1.4 mm and 2 mm, the length of clamping deformation should not be less than 2mm and the consistency of reflection points has significant influence on the signal quality. In the simulation of the cable tensile process, the frequency shift of the interferogram responds to the cable strain linearly. On this basis, a CCFPI sensor is fabricated and a sensing performance test is carried out. The test results show that the strain measured by CCFPI sensor is consistent with that measured by the dial gauge in the whole tensile process with a fit slope of 1.00492 and correlation coefficient of 0.998 67. In addition, the value measured by CCFPI sensor is also consistent with that measured by the fiber bragg grating in small strain range, showing that the measured results of the sensor are accurate and reliable. It is also found the CCFPI sensor mentioned in this paper has a resolution of 110με and failure strain of about 140000με.