根据光纤布拉格光栅(FBG)传感模型,提出了一种基于E型膜片和悬臂梁组合的FBG液位传感结构,建立了FBG反射中心波长随液面高度变化的数学模型。在0~100cm的测量范围内进行了实验研究,结果表明,液位对FBG反射中心波长调谐的最大漂移量为1.316nm,线性拟合度大于0.999,灵敏度为13.1pm/cm,与理论计算值(13.8pm/cm)比较,存在5.1%的相对误差。通过对理论模型的分析,改变E型圆膜片和悬臂梁的有关参数,可实现对传感器的灵敏度和量程的调整,使之更加实用化。
Based on the combination of E type diaphragm and cantilever beam,a new fiber Bragg grating(FBG) sensor is proposed to measure the liquid level.A mathematical model about the central reflection wavelength of fiber grating changing with the height of liquid is established.The experiments indicate that within the range of 0-100 cm,the largest central wavelength drifting is 1.316 nm,and the linearity is more than 0.999.Besides,the sensor sensitivity is 13.1 pm/cm which has a 5.1% relative error compared with the theoretical value.After analysing the theoretical model,by changing related parameters of the E type diaphragm and the cantilever beam,the sensor′s sensitivity and the range can be adjusted.