10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
A Low-Cost Unipolar Charger for Charged Particle Measurements
MEILU HE, Suresh Dhaniyala, Clarkson University
Abstract Number: 1439 Working Group: Instrumentation
Abstract Increasingly scientists are interested in mapping air quality at high resolution over large areas to accurately assess exposure to ambient particles. For such studies, a large number of low-cost particle sensors are required for large-area particle concentration monitoring. In response to such requirement, several low-cost sensors have been developed for particle concentration measurements. Almost all of these sensors operate on the basis of optical scattering, which means that particles smaller than ~ 300 nm cannot be detected by such sensors. The population of particles smaller than 300 nm often dominates ambient number concentration and possibly more important from a human health perspective. To detect these particles, we are developing a low-cost electrical-mobility based sensor, with particle concentrations measured by an electrometer. To boost sensor signal and detect particles under low concentrations, we developed a low-cost unipolar charger that is compact in size, and simple in design. Using a standard corona Tungsten wire and a compact HV, steady positive ions were generated and their concentration was measured. Additional electric field is applied to minimize particle contamination on the wire. Particle size dependent charging fractions were measured for the charger. We will present the design of the charger and its charging and transmission characteristics and some initial results of the integrated performance of the charger with the low-cost electrical-mobility sensor.