光纤光学相干膜盒压力传感器设计

Design of Optical Coherent Diaphragm Pressure Sensor

设计了一种新型光纤膜盒压力传感器,应用频率扫描光纤相干测距法感知波纹膜片位移量,从而得到压力测量值。设计的压力传感器应用单模光纤空间滤波特性进行测距,实现了对非光滑金属膜片表面的直接测距;压力膜盒通过退火工艺消除焊接产生的残余应力,改善了迟滞特性。实验结果表明,设计的压力传感器不仅比指针式膜盒压力表拥有更高的精度和灵敏度,同时又拥有光纤传感器远距离测量和抗电磁干扰的特点。对其中一种尺寸的压力传感器进行了标定,给出了压力与距离的特性曲线以及零点温度漂移曲线,其迟滞仅为0.2%,非线性度为0.7%。

A new optical diaphragm pressure sensor is designed which uses the frequency-scanning interferometry to measure the displacement of corrugated diaphragm so as to get the pressure value. The pressure sensor applies spatial filtering characteristic of single mode fiber for distance measurement, and direct distance measurement is achieved for non-smooth metal diaphragm. The pressure diaphragm eliminates residual stress generated from welding through annealing process, which improves hysteresis characteristics. The results show that the pressure sensor not just owns higher accuracy and sensitivity than pointer-type diaphragm pressure gauge, but also owns features of remote measurement and anti-electromagnetic interference of fiber optic sensor. Through calibrating the pressure sensor, characteristic curve of pressure, distance and zero temperature drift curve are given. The hysteresis is only 0. 2%, and the degree of nonlinearity is 0. 7.