An Aerosol Chemical Speciation Monitor (ACSM) for Routine Monitoring of the Composition and Mass Concentrations of Ambient Aerosol

摘要

Ambient particles are known to play a significant role in altering the chemistry and the radiative balance of the Earth’s atmosphere, reducing visibility, and adversely affecting human health. In order to address aerosol effects on health and the environment, there is a need for instrumentation which is capable of reporting the chemical and microphysical properties of ambient particles. We present here results on the development and demonstration of a compact aerosol mass spectrometer system, the Aerosol Chemical Speciation Monitor (ACSM) which measures aerosol mass and chemical composition of non-refractory submicron aerosol particles in real-time. The ACSM provides composition information for particulate ammonium, nitrate, sulfate, chloride, and organics and is designed and built around the same technology as our larger research grade Aerosol Mass Spectrometer (AMS) in which an aerodynamic particle focusing lens is combined with high vacuum thermal particle vaporization and mass spectrometry. The ACSM system is smaller, uses lower cost components and thus operates with lower performance than the research grade AMS. It is simpler to operate and maintain and is stable for long periods of time (months). The ACSM is designed for routine monitoring of PM with sufficient sensitivity to provide chemically speciated mass loadings and aerosol mass spectra at data rates up to 15 min for typical urban aerosol loadings. Results are presented from recent field deployments which compare the ACSM performance with AMS systems. Data quality and data analysis methods will be presented and areas of current development will also be discussed. .