It is used for measuring the concentration & mass of particulate matter (PM) i.e. (0.25 to 32 µm size) in real time. Dust monitoring instruments for indoor air quality have a long tradition at Grimm Aerosol. These optical laser light aerosol spectrometers monitor not only in real-time the dust concentration but also the particle size distribution in over 32 different size ranges and convert those results simultaneously to inhalable, thoracic, and alveolic fractions following the European and American regulations. Even the Nano particle size fraction is covered in a docent size ranges and can be expanded down to a few nanometers with our accessories.