Particle size analysis
PGA is based on the physical principles of laser diffraction. The diffraction of the laser light results from the interaction of light with the particles and can be mathematically described by the Fraunhofer or Mie theory. For a single spherical particle, the diffraction pattern shows a typical ring structure.
Measuring the intensity of diffracted light as a function of the angle, followed by a processing of these data by means of a mathematical model makes it possible to calculate the particle size distribution of the sample (large particle = small deflection (small angle), but high intensity).
Advanced systems use the Mie theory, covering not only the size but also the ratios can be determined.