夹持式封装低温敏FBG应变传感器的设计

设计了一种两端夹持式封装的低温敏FBG应变传感器.利用金属内、外管产生的膨胀差值引起的光栅波长变化量,与热膨胀和热光效应引起的光栅波长变化量抵消,实现温度补偿,金属内、外管隔及隔温套管与夹持支座内部均采用粘结剂连接后实现对光纤光栅的封装.标定试验表明:该传感器的温度灵敏度为0.78 pm/ ℃,是裸光纤光栅温度灵敏度的7.2%,大大降低了对温度的灵敏性,应变灵敏度系数为1.377 pm/ ℃.

Design of Holder Type Packaging Fiber Bragg Grating Strain Sensor with Low Temperature Sensitivity

A kind of fiber Bragg grating strain sensor with low temperature sensitivity was designed. There was the expansion difference which came from the thermal expansion coefficient and the inner tube and outer tube,also there existed the difference due to thermal expansion and thermo-optic effect. The deformations of fiber Bragg grating of these two kinds of differences could be offset to achieve temperature compensation. The adhesive was used to con-nect the inner tube and outer tube,so do the connection between separating warm casing and holder type tube. Hence,the packaging of fiber Bragg was realized. The experiment indicated that the temperature sensitivity coeffi-cient of the sensor was 0.78 pm/℃,which was 7.2% of the bare grating's,and the temperature sensitivity is greatly reduced. The strain sensitivity coefficient was 1.377 pm/με.