About ACSM

The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) measures quantitative particle mass loading and chemical composition in real-time for non-refractory sub-micron aerosol particles. It is designed for long-term unattended deployment and routine monitoring applications. It is available in two forms: the Q-ACSM, which features a quadrupole mass spectrometer, and the ToF-ACSM, which features a time-of-flight mass spectrometer. 

(Source and more information about the ACSM: www.aerodyne.com.)