10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
SEMS Transfer Functions under Fast Sequential Scanning
MARK KANAPARTHI, Suresh Dhaniyala, Clarkson University
Abstract Number: 1241 Working Group: Instrumentation
Abstract The size distribution measurements are routinely made using a Scanning Electrical Mobility Spectrometer (SEMS). These measurements are generally made over a reasonably long time period (large scan time). With decrease in the scan time of the operation, the discrepancy between the classically predicted transfer function and the actual transfer function is more pronounced. As the scan time approaches the average residence time of the particle in the classifier section, an increasing fraction of particles that are injected during the scan are extracted in the successive scan. To calculate the transfer function under such conditions, the traditional trajectory approach by Dubey and Dhaniyala (2008) can’t be employed since the particles encounter a combination of an exponentially increasing voltage with an exponentially decreasing voltage, i.e. the Arrival time Transfer Function (ATF) can’t be translated in time as was done previously. The ATF’s have be calculated for every mobility to compute the mobility transfer function. The mobility transfer function computed is used to calculate the instrument response. The implications of inverting data under a combination of up-scan and down-scan is discussed.