光加热光纤光栅阵列液位测量方法研究  

Liquid level Measurement Method Based on Laser Heating Fiber and Fiber Bragg Grating Array

作　　者：戢雅典 范典[1] 王宇琦 周次明[1] JI Yadian;FAN Dian;WANG Yuqi;ZHOU Ciming(National Engineering Research Center for Optical Fiber Sensing Technology and Network,Wuhan University of Technology,Wuhan Hubei 430070,China;School of Information Engineering,Wuhan University of Technology,Wuhan Hubei 430070,China)

机构地区：[1]武汉理工大学光纤传感技术与网络国家工程研究中心,湖北武汉430070 [2]武汉理工大学信息工程学院,湖北武汉430070

出　　处：《传感技术学报》2024年第6期959-966,共8页Chinese Journal of Sensors and Actuators

基　　金：国家自然科学基金(52071245,61975157,62275204);国家重点研究与开发计划(2021YFB3202901)。

摘　　要：安全可靠的液位测量是现代工业领域的重要技术需求之一,提出一种基于光加热光纤光栅阵列的液位测量方法,即利用泵浦光加热掺钴光纤,控制温度场,利用光栅阵列测量温度场分布,由于气液导热性能的差别,气液界面处温度突变,从而确定液位。实验中,将掺钴光纤与密集光栅阵列紧密固定在一起,将1.5 W的泵浦光输入衰减系数分别为0.71 dB/cm和0.28 dB/cm的掺钴光纤中,沿着光传播的方向,温度变化均呈指数函数衰减。液位测量的精度与范围由主要取决于泵浦光功率、掺钴光纤吸收系数,经对比最终选定0.28 dB/cm的掺钴光纤作为液位实验的加热光纤。实验测量了不同液位下的温度场分布,证明了利用测量温度分布来测量液位的可行性,液位变化范围0~88 mm以内的误差为2 mm。所提出的传感系统结构简单,成本低廉,在液位测量方面具有潜在的应用价值。A safe and reliable level meter is an indispensable device in modern industry.A liquid level measurement method based on optical heating and optical fiber grating array is proposed.The principle is that a laser heats the cobalt-doped optical fiber,controls the temperature field of the fiber,and the grating array is used to measure the temperature field distribution.Due to the difference of gas-liquid thermal conductivity,the temperature at the gas-liquid interface changes abruptly,so as to realize the determination of the liquid level.In the experiment,the cobalt-doped optical fiber and the dense grating array are tightly fixed together,and the temperature change is atten-uated as an exponential function along the direction of light propagation when 1.5 W high power pumped light is input into the cobalt-doped optical fiber with attenuation coefficients of 0.71dB/cm and 0.28dB/cm,respectively.The accuracy and range of liquid level meas-urement mainly depend on the pump light power and the absorption coefficient of cobalt doped optical fiber.After comparison,0.28 dB/cm cobalt doped optical fiber is finally selected as the heating optical fiber for liquid level experiment.The temperature field distributions at different liquid levels are measured.The experiment proves that it is feasible to measure the liquid level by measuring the temperature dis-tribution.The error is 2 mm within the range of 0-88 mm.The experiments show that the proposed sensing system is simple in structure and low in cost,and has potential applications in liquid level measurement.

关 键 词：光纤传感技术 液位测量 布拉格光栅阵列 光加热 温度调制 温度分布 

分 类 号：TN253[电子电信—物理电子学]