FAQ - Pharmaceutical/Life Sciences Particle Counting

Lasair II 550L particle counter

Question
How does the Lasair II 550L calculate the # of particles per sample volulme?

Answer

As an aerosol particle counter samples air at a fixed flow rate (50 L/min for the Lasair 550L), it counts the number of particles it observes during the sample interval. Because the flow rate is constant and the duration of the sample interval is known, the sample volume can be calculated by the particle counter. The number of particles is then divided by the sample volume.

For more information on Sample Volume, read How Many Particles, How Much Sample Volume?