Real-Time Dust Monitoring. Any Environment. Any Application All DustTrak™ II Aerosol Monitors are continuous, real-time, single-channel, 90° light-scattering laser photometers that are used to determine the mass concentration of aerosols. A built-in pump allows for the use of a variety of size-selective inlet conditioners to measure aerosol concentrations corresponding to PM10, PM2.5, PM1, or respirable size fractions.