差动光纤Bragg光栅压力传感器的研究

Study on pressure sensor with differential fiber bragg gratings

由周边固支的圆形平膜片作为传感器的弹性元件,膜片两侧的压力差使膜片产生挠度。两个相同特性的光纤Bragg光栅分别粘贴在平膜片的径向和切向上,构成差动压力传感器,解决了光纤Bragg光栅的温度应变交叉敏感问题。如果气压过大,膜片产生大挠度现象时,必须考虑平膜片的中面的拉伸,测量系统可以自动修正平膜片的挠度方程。实验结果表明,系统压力测量线性度为0．2(％F·S),重复性为0．1(％F·S),分辨率为5×10-4MPa。

The elastic component of sensor is composed of the circular flat film which is fixed around. The difference of the pressure between the two sides of the film causes deflexion. Two fiber Bragg gratings which have the same properties are pasted along the normal to and tangential to the flat film respectively, thereby consisting of the differential pressure sensor and solving the issue to the cross of temperature strain of fiber Bragg gratings. If the atmospheric pressure is too high, large deflexion phenomenon will appear. The measurement system can amend the flexibility equation automatically. The result of the experiments shows that the linearity of the pressure measurement system is 0. 2 % , the precision is 0. 1 % , and resolution is 5×10-4 MPa.