Laser diffraction for particle size distribution

The size distribution of passing particles can be determined with a laser diffraction measurement. Depending on the particle size, the monochromatic laser light is diffracted to a greater or lesser extent. The characteristic, ring-shaped intensity distribution is detected by numerous detectors and converted into a particle size distribution using a physical model (according to Mie or Fraunhofer). Dry powders and granules can be measured with the Dry Powder System (DPS). For suspensions, the Universal Liquid Module (ULM) is used which has additional polarization detectors.