温度自补偿型光纤Bragg光栅土压力传感器设计

Design of temperature self-compensation fiber Bragg grating soil pressure sensor

针对传统土压力传感器长期稳定性差、抗电磁干扰能力不强以及组网难度大等问题,根据传感器与土介质的匹配原则,设计了一种光纤Bragg光栅（FBG）温度自补偿土压力传感器,可实现温度和土压力2个参量的同时测量.对传感器灵敏度系数、匹配性等参数进行了理论分析计算.根据分析结果,加工封装传感器并对其进行了压力校准和温度自补偿性能实验.实验表明：传感器的输出波长分别与温度和土压力均呈线性关系,压力灵敏度系数为272.19 pm/MPa,输出分辨率为0.36％,线性相关度为99.989％;温度灵敏度系数为21.16 pm/℃,线性相关度99.998％,在0～40℃范围内具有良好的温度自补偿能力,其性能参数符合工程应用要求.

Aiming at problem of poor long-term stability, and poor anti-electromagnetic interference capability and difficult networking of traditional soil pressure sensors, a fiber Bragg grating（FBG） soil pressure sensor is designed based on matching principle of soil medium and pressure transducer to fulfill temperature and soil pressure monitoring simultaneously. The sensitivity coefficient, matching are analyzed theoretically. According to analysis result, the sensor is packaged and its pressure is calibrated and temperature self-compensation property experiment are carried out. Experimental results indicate that output wavelength shows good linear relation with soil pressure and temperature individually, coefficient of pressure sensitivity is 272.19 pm/MPa, resolution ratio is 0.36 %, with a linear correlation of 99. 989 % ; temperature sensitivity coefficient is 21.16 pm/℃ with a linear correlation of 99. 998 % ,temperature self-compensation capability at range of 0 - 40 ℃ is good, which meet requirements of engineering application.