AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Evaluation of a Low Flow Particle Concentrator for Atmospheric Aerosols
LEAH WILLIAMS, Philip Croteau, John Jayne, Thorsten Hohaus, Douglas Worsnop, Susanne Hering, Gregory Lewis, Aerodyne Research, Inc.
Abstract Number: 220 Working Group: Instrumentation and Methods
Abstract We present the evaluation of a low flow particle concentrator developed by Aerosol Dynamics for use with the Aerodyne aerosol mass spectrometer (AMS) and aerosol chemical speciation monitor (ACSM). These instruments sample at a flow rate of less than 0.1 lpm. The low flow concentrator uses a single, continuous-wick growth tube with three temperature stages and has a low output temperature and dew point. A focusing nozzle separates the concentrated aerosol particles from the excess flow and results in a concentration factor of 8 to 10. We characterized the concentrator in laboratory experiments with particles of known concentration and size. We also evaluated the concentrator for ambient measurements by sampling for three weeks with two AMS instruments, one behind the concentrator and one on a bypass line. The concentrator provided a stable concentration factor over this time period and required no maintenance. We observed no significant changes in the particle chemical composition or size distribution after concentrating. The low flow concentrator will provide a valuable enhancement for AMS and ACSM measurements in environments with very low ambient mass loadings.