基于光纤传感的多通道泥沙浓度测量研究

Multichannel measurement method of suspended sediment concentration based on optical fiber sensing

基于光学背向散射原理设计开发了一种光纤多通道泥沙浓度测量装置。该泥沙浓度测量装置入水探头直径仅为2.5 mm,对待测水体运动的影响较小,同时具有量程大、采样快和多通道同步测量等特点,可以满足室内实验泥沙浓度的测量。通过调整测量装置的光源强度调节测量量程和测量精度,可以实现不同泥沙浓度的测量需求。中值粒径为46.5μm的粉沙浓度率定结果表明,该测量装置对粉沙可实现最大浓度达150 kg/m^3的高含沙浓度测量。该装置已成功应用于振荡格栅水槽均匀紊流中粉沙浓度的多通道同步测量。

Based on the principle of optical backscatter,this study develops a multi-channel device for sediment concentration measurement using micro-sensors of optical fiber.The device has a small-size probe of only 2.5 mm in diameter and produces a very slight effect on the motion of fluid to measure.It also has the advantages of large range,high sampling frequency,and synchronous measurement of multi-channels,satisfying the requirement of most laboratory experiments.The measurement range and accuracy can be adjusted by tuning light source intensity to meet the needs of different measurements.Calibration using suspended silt with a median particle diameter of 46.5 micron shows that silt concentration of up to 150 kg/m^3 can be measured.The device was successfully applied to synchronous measurement of multi-channel concentration for silt suspension in the flows of homogeneous turbulence on an oscillating grid flume.