1.1 This standard (Part 4) covers the method for the quantitative determination of grain size distribution in soils.
1.1.1 Two methods are given for finding the distribution of grain sizes larger than 75-micron IS Sieve; the first method, wet sievings shall be applicable to all soils and the second, dry sieving, shall be applicable only to soils which do not have an appreciable amount of clay.
1.1.2 For the determination of distribution of grain sizes smaller than 75-microns the pipette method is given as the standard method; the hydrometer method is given as a subsidiary method. This method shall not applicable if less than 10 percent of the material passes the 75-micron IS Sieve ( determined as given in 4 ).