河流中的悬移质通常含有粗粒(D>0.05毫米)和细粒(D<0.05毫米)两种成分,其中粒径在0.05毫米以上的粗粒含量较少(每1000毫升水样中一般不超过1.0克)。由于沙量少,很难用筛析法分析,因此这种粗样必须采用粒径计法分析(以下简称“粒桁”)。但用粒径计法分析粗沙存在沉速偏大和级配偏粗的现象,因此,分析成果必须 Suspended solids in rivers generally contain two components, coarse (D> 0.05 mm) and fine (D <0.05 mm), with less coarse particles of 0.05 mm in diameter or more No more than 1.0 gram). Due to the small amount of sand, it is difficult to analyze by sieve analysis. Therefore, this coarse sample must be analyzed by particle size analyzer (hereinafter referred to as “grain truss”). However, the method of particle size analysis of coarse sediment is too large and the phenomenon of coarse gradation gradation, therefore, the results of the analysis must