6. Conclusion

This article provides an overview of the principles and applications of optical particle sizing techniques for flowing particles ranging in size from nanometers to millimeters. See the summary table in figure 3 . Many of these are still laboratory techniques, as commercial offerings are limited despite the very great needs in this field.

There is no single solution that covers all needs in terms of size range and morphology, measurement distance and optical density, or the nature and scale of the statistics. Some techniques have wider operating ranges and are more versatile than...