Tag Archives: PSD

Laser Diffraction PSD Method

This is one of the dominant techniques many industries use to measure particle size dissolution.


It involves the use of complex technology, standard and computerized data processing. Mie Theory of light scattering is always employed in Laser PSD method development to calculate the size of particles that are responsible for different light scattering patterns.

The operations of Laser Diffraction Technique

  1. The Presence of Laser Diode:  A laser diode is the device that produces a single but coherent beam of light.
  2. Light Detectors: they could be two or three. They help to collect the data of light intensity that scatter at different angles.
  3. Lenses: they are always in front of the particles. They focus the light rays that pass through the particles.

Using PSD method development, a laser beam of light will pass through the particles. All particles will scatter at different diffraction angles. Small particles scatter light at large angles and vice versa. Thus, the data of the particle size dissolution will be easy to calculate.Laser_diffraction_analysis_small_particle.


Benefits of Using Diffraction PSD Method.


As complex as PSD method development may look, it is very simple and fast to operate. It has an advantage over sieving technique because it can be used to measure liquids, sprays,powders and aerosols.

The use of special light detectors make it faster to collect the result or data of particles size distribution. Also, it produces high level of reproduction and precision. There is absence or lesser work hazard with its use. No industrial worker can intrude, interrupt nor disturb the process once it is  in progress.


Disadvantages of Diffraction PSD Measurement


The resolution of Laser PSD method development diffraction varies with the size or amount of the particle. If there are mistakes in the refractive indices, there will be errors in the results.

To cap it all, it does not allow the measurement of  two or more particles with different optic properties. This is due to the fact that the use of laser is monochromatic in nature. That is, it only produces a beam of light.