An aerosol particle counter works on the principal of either light scattering or light blocking. An aerosol stream is drawn through a chamber with a light source (either Laser Based Light or White Light). When a particle is illuminated by this light beam, it is redirected or absorbed. Light scattered by a single particle in a specific direction in relation to the original direction has a unique signature which relates to the size of the particle. This allows for sizing and counting of individual particles.

A particle counter is made up of 4 components:

  1. Light Source (Gas Based Laser, Solid State Laser Diode, High Intensity Light)
  2. Photo Detection Electronics
  3. Sample Flow System
  4. Counting Electronics