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引言为了估算河流中的含沙量或为了进行水质分析,常常需要从河流中采集悬移质沙样。在取样地点偏远或取样时间不规则时,往往利用自动泵或取样器取样。当取样器的管嘴指向上游时常会被树叶之类的杂质堵塞,因而通常将管嘴方向设置成与流向成适当角度或指向下游。以往的研究已经证明,如果取样器管嘴角度设置不当,即对准且顺直平行于水流,将会给取样过程带来相当大的误差(联邦内务部泥沙专业组,1941)。设置取样管嘴相对于水流的角度时应使得被取沙样随水一起
Introduction In order to estimate the sediment concentration in rivers or for water quality analysis, it is often necessary to collect suspended sediment samples from rivers. In the remote sampling locations or irregular sampling time, often using automatic pump or sampler sampling. When the nozzle of the sampler is pointed upstream, it is often clogged with impurities such as leaves, so the nozzle orientation is usually set at an appropriate angle to the flow direction or downstream. Previous research has demonstrated that there is considerable error in the sampling process if the injector nozzle angle is set incorrectly, ie aligned and straight parallel to the flow of water (Federal Ministry of Interior Sediment Professional Section, 1941). Set the sampling nozzle angle relative to the water should be taken sand samples taken together with the water