Air pollution is one of the biggest health threats. An important factor for air quality is the presence of particles in air. Methods analyzing air quality are mostly focusing on the size of the particles, because it is defining how deep particles can enter the lungs.

The differentiation of the particles can also be done, but it is generally more time consuming and the used methods require a laboratory analysis. When the air quality should be monitored in multuple positions or over a long period of time, laboratory analysis can only be done on random samples, because of its high analytical expenses.