Randomization of particle orientation

The poor repeatability in the laser diffraction results is possibly due to the fact that a) the randomness of particle orientation in scattering volume may be different when using different designs of sample modules to circulate the particles b) different measurement sensitivities may exist for particles of various sizes due to differences in the optical design of the instruments or c) the algorithms used in the size retrieval process and the approximations used in obtaining apparent values (equivalent spherical diameters) for non-spherical particles are different between manufacturers. 

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