There are two well-established methods for determining the particle size of a sample: dynamic light scattering and laser diffraction. Choosing which particle size analysis method to use requires consideration of the expected size range, the sample type (liquid or solid), the amount of available sample, the chemical stability, and the application field. However, the physical principle behind each technique is also important, and the choice of the most suitable one is not always straightforward.

This article describes the principal differences between dynamic light scattering and laser diffraction, and it also provides an overview of the options for data interpretation and possible comparison.