为了实现对液压管路中液压油的压力和温度检测, 研制了一种EFPI-FBG复合压力温度传感器。对该传感器的压力特性以及温度特性进行研究。首先, 介绍了以光纤F-P腔和光纤光栅为敏感元件, 利用环氧树脂将EFPI-FBG复合结构经过封装保护构成压力温度传感器结构以及制作方法。接着, 建立了压力温度传感模型, 对传感器受力进行了理论分析, 并使用Matlab和有限元软件分析传感器的压力灵敏度和温度灵敏度。最后对传感器进行压力和温度实验验证。实验结果表明, 该传感器的压力灵敏度为2.83 μm/MPa, 温度灵敏度为1.97 μm/℃, 温度监测范围为10~80 ℃, 应用于压力测量时的有效工作温度为20~65 ℃。此EFPI-FBG复合压力温度传感器具有良好的线性度, 较小的回程误差, 灵敏度高, 抗震性能好, 可用于液压管路中液压油的压力和温度测量。

To realize pressure and temperature detection of hydraulic oil in hydraulic pipelines, a new type of fiber optic pressure temperature sensor was designed in this study, and its pressure and temperature load characteristics were investigated. First, a fiber-optic Fabry-Perot (F-P) cavity and fiber grating were used as the sensitive components, and the Extrinsic F-P Interferometer-Fiber Bragg Grating (EFPI-FBG) composite structure was encapsulated and protected by epoxy resin to form the pressure temperature sensor structure. The manufacturing method was next presented, and the pressure temperature sensing model was established. A theoretical force analysis of the sensor was then conducted, and sensor pressure and temperature sensitivities were calculated using MATLAB and the finite element method. Finally, the sensor was tested under pressure and temperature experiments. Experimental results indicate that the pressure sensitivity is 2.83 μm/MPa, the temperature sensitivity is 1.97 μm/℃, and the temperature monitoring ranges from 10 to 80 ℃. When the sensor is applied to a pressure measurement, the effective operating temperature ranges from 20 to 65 ℃. The EFPI-FBG composite pressure and temperature sensor is shown to have good linearity, small backlash error, high sensitivity, strong anti-interference ability, and good seismic performance. It can be used to measure hydraulic oil pressure and temperature in hydraulic pipelines.