AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Investigation of Dust Dynamics Using Imaging Techniques
WING-TAK LAI, Seungkoo Kang, Sheng-Chieh Chen, David Y. H. Pui, TSI Inc
Abstract Number: 720 Working Group: Instrumentation and Methods
Abstract The dust dynamics in terms of its size, concentration and velocity are important information for many different applications. For example, the use of the dusts for calibrating particle instruments, for correlating the dust size with health effect in exposure studies as well as using the dusts to challenge different purpose filters all rely on these dynamics. In situ measurements for these dynamics of dusts using particle instruments usually do not take the transport loss into account, especially for dusts larger than 5 microns, which can lead to a severe error on sizing and concentration measurements. This study proposes a non-intrusive imaging technique to determine the dust dynamics, which can avoid the error due to the transport in the experimental system. The system is made up of a 8 Mpixel CCD camera with 5.5 micron pixel size, x12 micro-lens, a 532 nm light source double-pulsed laser and a commercial software, Insight 4G (TSI Inc., Shoreview, MN). By using the x12 lens, the pixel size of the camera is reduced to ~0.4 microns, allowing the ability to measure dust particles of size down to 2 micron when a 5 x 5 pixel region is considered to determine the size. Since the system is based on the measurement of “shadow” of the dust particle with laser illumination in the forward scatter direction, the size of the shadow is measured directly without any assumption pre-conceived shape of the dust particle. The concentration is estimated based on the inspection area size and the number of dusts detected over a time period. In addition to the size and concentration of the dusts, velocity is also measured by the system to provide flux information.