OBS-3A在悬移质含沙量测验中的应用研究

传统悬移质含沙量主要采用烘干法测量，其操作繁琐、费时费力且无法实时连续施测，近年来越来越多地被光学仪器法（OBS-3A）替代。介绍了OBS-3A的测量原理、仪器结构，通过OBS-3A与传统方法测验悬沙浓度（SSC）比测试验，分析了传统方法测沙与OBS-3A测沙结果之间的关系。结果表明，只要样本覆盖一定范围且样本数达到一定数量，浊度和SSC之间能得到较好的相关关系。推荐采用0.6 H的水样率定工作曲线。OBS-3A的测量结果受泥沙粒径的影响较大，颗粒粒径越小，OBS-3A就越敏感，所测得结果也更为准确。

Study on application of OBS-3 A in suspended sediment concentration measurement

The conventional drying measurement method for suspended sediment is complex and time consuming, and the real-time measuring is impossible, so it is replaced by OBS-3A increasingly. The principle and structure of the OBS-3A are introduced. Through the comparative test of suspended sediment concentration (SSC) measured by conventional method and OBS-3A, we analyze the relationship between the results of conventional method and OBS-3A. It shows that the satisfying relationship between NTU (turbidity) and SSC can be obtained in the case that the sample covers certain scope and reaches a certain number. The water sample at the depth of 0.6H is recommended to calibrate the curves. The measurement result of OBS-3A is strongly affected by the sediment grain size, namely the smaller the size is, the more sensitive the OBS-3A is and the results will be more accurate.