Grain size analysis of coarse grained soils is carried out by sieve analysis, where as fine-grained soils are analysed by the hydrometer method or the pipette method. In general, as most soils contain both coarse and fine-grained constituents, a combined analysis is usually carried out. In the combined grain size analysis, a soil sample in the dry state is first subjected to sieve analysis and then the finer fraction is analysed by the hydrometer or pipette method.