一种内嵌喷嘴差压式FBG流量传感器

针对传统液压系统流量测量中存在的传感器体积 较大、测量精度不高等问题,研究并设计一 种内嵌喷嘴差压式光纤 Bragg 光栅(FBG ) 流量传感器。在分析 FBG 及差压式流量测量原理的基础上, 选用标准喷嘴作为节流元件,通过将 FBG 沿径向粘贴于圆形平面膜片上,敏感被测流体经过喷嘴节流口 后在两侧所产生的压力差。推导了 FBG 中心波长偏移与被测流体流量变化之间存在的数学关 系,并通 过试验平台测量了传感器的静压特性以及动态流量特性。测试结果表明,传感器中 FBG 平面膜片的静压力 差压灵敏度为 0.712nm/MPa ,而差压式 FBG 流量传感器的灵敏度为 0.067L/s 。本文传感器具有测量精度高、 体积较小和环境适应能力强等优点,且易于实现传感复用并构成准分布式检测网络。

An embedded nozzle differential pressure style flow sensor based on FBG

In view of the problems that the sensor volume is large,and measurement accurac y is low, which exist in the traditional hydraulic detecting system,an embedded nozzle differential p ressure flow sensor based on f iber Bragg g rating (FBG) is researched and designed.Based on the measurement principles of FBG and the differential pressure type flow sensing, the standard nozzle is chosen as the throttling element,and the FBG is pasted on the circular planar diaphra gm with radial direction ,which is used to measure the pressure difference between the two sides of the nozzle when the tested fluid passes through the nozzle. The mathematical relationship between the tested fluid flow and the FBG central reflected wavelength shift is deduced,and the static pressure and dynamic flow characteristics of the sensor are tested by experiment in this paper. According to the test results,the differential pressure sensitivity of the FBG planar diaphragm under the static pressure of the sensor i s 0.712nm/MPa,and the f low sensitivity of the differential pressure FBG flow sensor is 0.067L/s. This sensor has the advantages of high measurement accuracy,small volume and good env ironmental adaptability,and easy to implement multiplex and distributed sens ing network,therefore has a comparative advantage and broad prospects in flow sensing applications.