AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
MAGIC Spider: A Fast, Compact Scanning Electrical Mobility Spectrometer for UAV Deployment
STAVROS AMANATIDIS, Steven Spielman, Gregory Lewis, Susanne Hering, Richard Flagan, California Institute of Technology
Abstract Number: 310 Working Group: Instrumentation and Methods
Abstract Obtaining accurate particle size distributions aloft, especially in the ultrafine size range, is a challenge when power and weight are limited. Unmanned Aerial Vehicles are used increasingly to map atmospheric aerosols aloft, and in remote areas, but payloads are limited. To meet this need we have developed a new, highly portable mobility-based particle sizer. Our instrument, the “MAGIC Spider”, combines the “Spider DMA”, a compact radial-flow differential mobility analyzer designed by Caltech, and the “MAGIC” CPC, a self-sustaining, motion-tolerant, water-based condensation particle counter designed by Aerosol Dynamics Inc. The Magic Spider is compact, weighs 1.5 kg, and requires 12 Watts of power. It provides mobility-based particle sizing in the 10 – 500 nm range in as little as few seconds while operating on low flowrates (0.6 – 1.2 L/min sheath, and 0.3 L/min aerosol flow). It has been designed to provide sufficient statistics for atmospheric size distribution measurements in remote as well as urban locations.
Here, we present the key features of the integrated MAGIC Spider system, including determination of its transfer function over a range of sheath and aerosol flow rates. We examine both stepping and voltage-scanning operation, with scan times ranging from 90 s to as little as 1 s. The MAGIC Spider is compared against a benchtop Scanning Mobility Particle Sizer (SMPS) for both laboratory and ambient aerosols. The data show that particle size distributions agree well, as do the number concentration, geometric mean diameter and other integral parameters. The data further demonstrate the value of compositing fast scans over the benchtop’s two-min averaging period when examining rapidly changing aerosols.