Many natural and manufactured materials occur in a disperse form, which means that they consist of differently shaped and sized particles. The particle size distribution, i.e. the number of particles of different sizes, is responsible for important physical and chemical properties.
Sieving is cost effective for particle sizes greater than 75
μ, although the technique can be used for some materials of smaller size if the method can be validated. Assuming the relevant standards and clean, wellmaintained equipment that conforms to the standards are used, sieving can provide an accurate and reproducible measure of particle size distribution within a sample.