AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
A CAPS-Based Single Scattering Albedo Monitor
Timothy Onasch, Paola Massoli, Paul Kebabian, ANDREW FREEDMAN, Aerodyne Research, Inc.
Abstract Number: 171 Working Group: Instrumentation and Methods
Abstract We present data detailing the performance of a particle single scattering albedo (SSA) monitor that incorporates both a CAPS (Cavity Attenuated Phase Shift)-based optical extinction measurement and an inverse nephelometer in the same measurement volume. Since an absolute extinction measurement is provided, the scattering channel can be calibrated with any non-absorbing particle (e.g., a PSL) or gas (other than air). The monitor demonstrates noise levels (1 s sample time) of less than 1 Mm$^(-1) in both channels. Measurements of the single scattering albedo of bare and organic coated soot particles using both this monitor (the CAPS PMssa) and another instrument which comprised a cavity ring down-based extinction system coupled to a photoacoustic particle absorption spectrometer (courtesy of C. Cappa, U.C. Davis) showed excellent agreement between the two. The SSA monitor can be operated in any wavelength region compatible with the availability of high reflectivity mirrors, LEDs and photomultiplier tube PMT) photocathodes. At present, the available wavelength band is restricted to the 400-700 nm region.