温度精度补偿的光纤光栅土压力传感器

Fiber Bragg Grating Soil Sensor with Precision Temperature Compensation

提出一种新颖的基于温度补偿的光纤光栅土压力传感器。该传感器结构具有平面膜片特点,带有预拉力的测压光栅两端固定于膜片内表面上,膜片在外界压力作用下产生向内的挠度,拉动测压光栅以实现压力传感。温补光栅单端固定,栅区呈自由状态,使之对外界压力不敏感,可以在测压过程中做到温度精确补偿。测压光栅采取与平面膜片两端粘接的固定方式,可以避免光栅波峰分裂的现象,又消除了力的中间传递,实现压力高精度测量。实验中,传感器在不同温度下所获得的压力值的范围小于0.4%FS;基于0.5 MPa的压力测量范围下,压力精度有0.38%FS。

A novel fiber Bragg grating(FBG)soil with high precision temperature sensor is proposed.The sensor is based on the structure of plane diaphragm.Both of the ends of the pressure sensing FBG(PS FBG)with pretension are fixed on the internal surface.Axial displacement occurs under external pressure and pulls the PS FBG to realize pressure measurement.The temperature compensating FBG(TC FBG)is in the state of freedom for being fixed by single-end.So it is insensitive to external pressure and achieves the aim of precision temperature compensation.The fix mode of PS FBG can avoid the split of its peak.Meanwhile,it can realize precision pressure measurement without strain delivery among structures.In the experiment,the pressure measurement fluctuation of the sensor is less than 0.4%FS under different temperature.The pressure precision reaches 0.38%FS in the rage of 0.5MPa.