Abstract View
Re-examination of the CAPS PMssa Monitor Scattering Channel Truncation
Brian Heffernan, Stephen Jones, Timothy Onasch, ANDREW FREEDMAN, Aerodyne Research, Inc.
Abstract Number: 664
Working Group: Instrumentation and Methods
Abstract
We present measurements as well as detailed modeling of the truncation effect in the scattering channel of the PMSSA monitor. Wavelength (450-780 nm) dependent measurements of relative scattering intensities as a function of optical extinction are determined using both polystyrene latex (PSL) and ammonium sulfate particles. These particles are size selected using either a differential mobility analyzer (DMA) or an aerodynamic aerosol analyzer (AAC). The effects of the degree of the non-monodisperse nature of the measured particles, determined using an optical particle counter (OPC), will be discussed. We will also present detailed Zemax-based ray tracing modeling of the optical system which includes the effects of multiple reflections caused by the presence of a glass tube in the integrating sphere. Finally, a comparison with recently published data by other researchers will be made.