FBG传感对应变,温度及湿度的同时测量

The Simultaneous Measurement of Strain,Temperature and Humidity by FBG Sensors

为更好地解决交叉敏感这一光纤光栅应用中的瓶颈问题,该文从光纤布喇格光栅(FBG)的传感理论出发,分析了光纤光栅在同时测量应变、温度及湿度时交叉敏感的物理机制。通过给光纤光栅外层镀湿敏材料和温敏材料,推广了双光栅法解决交叉敏感的思路,采用三光栅法实现同时对应变、温度及湿度的测量,并设计了相应的解调方案。通过控制步进电机对基于悬臂梁的匹配光栅施加压力或拉力,从而与传感光栅进行匹配,能对传感光栅的波长漂移量进行高精度的测量。

The crosssensitivity is a bottleneck for fiber grating sensor applications. Based on the sensing theory of fiber Bragg gratings, the physical mechanism of the crosssensitivity in the simultaneous measurement of strain, temperature and humidity is analyzed. The thinking of doublegrating method for solving the problem of crosssensi tivity has been expanded by coating the humiditysensitive material and temperaturesensitive material on the out player of fiber grating. The simultaneous measurement of strain, temperature and humidity has been realized by using the threegrating method and the relevant demodulating scheme has been proposed. The highprecision meas urement of the wavelength shift of sensing grating can be realized by applying pressure and pull on the cantilever based match grating to match with the sensing fiber Bragg grating.