Laboratory measurement of particle size

There is an abundance of methods available for the measurement of particle size distributions and many excellent textbooks exist which review the field in great depth. Because of the limited scope of this chapter only a short review of the methods particularly relevant to solid-liquid systems is given. 

5 number of points on the distribution (or perhaps just some measure of central tendency) required  

8 cost of accessories such as sample preparation, evaluation of data etc.  

It should be noted that many of these factors are inter-related and their relative importance varies in different applications. 

As was stated in the introduction, Stokes diameter jcst is usually used to characterize particle size in those applications where it is the behaviour of particles in liquids that determines the separation efficiency and other operational characteristics of the separators (e.g. in sedimentation, centrifugation and hydrocyclones). Methods that measure Stokes diameter, such as sedimentation or fluid classification, have therefore been used extensively in this field. Although preference is naturally given to wet methods, air classification is also widely used. 

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