模型试验含沙量量测技术研究

Measurement technology and model test of sediment concentration

含沙量是河工、港工物理模型试验主要测量要素之一,现有的模型试验含沙量测量仪具有测量范围窄、相对误差大、重复性低等缺点,制约着物理模型试验含沙量的测量范围和试验准确性。介绍了一种自主研制的无线实时含沙量测量仪,该测量仪采用光电测量原理,将光信号转换成电信号,实现含沙量的实时在线测量。通过分析光电法含沙量测量仪的基本原理、硬件系统设计,分别研究了含沙量与透射光强、散射光强、透射光功率之间的变化关系,提出采用透射光与90°散射光相结合方法测量含沙量。经多组试验研究获得含沙量算法及其实现方式,确保含沙量测量的相对误差小于5%。本研究采用不确定度分析方法,分析新研制的含沙量测量仪的可靠性,试验表明仪器的不确定度小于0.4。

Sediment concentration is one of the main targets of the river and harbor physical model experiments.With narrow measuring range,large measurement error and low repeatability of faults,the existing sediment concentration technology restricts the test range and accuracy of physical model experiments.This paper introduces a new wireless real-time sediment concentration measuring instrument.It adopts photoelectric measuring principle,which realizes real?time online sediment concentration measurement by converting light signals into electrical signals.This paper mainly introduces the basic principle and hardware system design of the sediment concentrationmeasuring instrument.The connection among transmission intensity,scattering intensity,optical power andsediment concentration is studied,and a method is proposed for measuring sediment concentration by combining transmission and90°scattering light.In order to achieve the requirement that the relative error of the sedimentcontent is less than5%,the algorithm and implementation through multiple experimental studies are realized.The reliability of the newly developed instrument based on the uncertainty analysis method is analyzed.The experiment data show that the uncertainly of the sediment concentration measuring instrument is less than0.4.