APS

The aerodynamic particle sizer (APS) is a particle size spectrometer that measures both the particle aerodynamic diameter based on particle time of flight and optical diameter based on scattered light intensity. The APS provides the number size distribution for particles with aerodynamic diameters from 0.5 to 20 micrometers and with optical diameters from 0.3 to 20 micrometers.

The APS is part of the aerosol observing system (AOS).