Comparison of Aerosol Loss Effects in a Continuous-Flow Atmospheric Chamber Under Different Operational Configurations
KATHERINE PIERRE-LOUIS, Erin O'Leary, Bruno Loyola San Martin, Joseph Woo,
Lafayette College Abstract Number: 598
Working Group: Instrumentation and Methods
AbstractLaboratory-scale atmospheric chambers are a ubiquitous method for the characterization of aerosol emission and growth. To properly account for the overall mass balance of specific aerosol concentrations, losses to the internal walls and surfaces, β, must be quantified prior to measurement. This loss term largely assumes constant, uniform mixing within the chamber airspace; however, for smaller chambers, local convection due to entrance and exit flow effects may result in shifts to the overall mixing that occurs in practice. This study quantifies and statistically compares the wall loss factors of a 0.8m
3 continuous-flow chamber under a variety of operational conditions (total flow throughput, ambient RH, attached equipment actively pulling exit flow.) It was found that while connection to active vacuum pump operation had no statistically significant effect, air flow rate, aerosol diameter, and relative humidity had a statistically significant effect on wall loss coefficients.