AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Design and Testing of an Inhalable Particle Spectrometer
KIMBERLY ANDERSON, Mwangi Ndonga, David Leith, Jordan Rath, Azer Yalin, John Volckens, Colorado State University
Abstract Number: 256 Working Group: Instrumentation and Methods
Abstract Large particles (dp > 10 micrometers) exist in many atmospheres (e.g., workplaces, confined spaces, wind-blown dust). Although such particles can contribute up to 50% or more to the inhaled aerosol mass following exposure, very few instruments exist to count and size such particles in situ. Large inhalable particles deposit primarily in the oral and nasal cavities, with subsequent health effects targeting the upper respiratory system. Symptomatic health effects such as acute or chronic rhinitis, chronic pharyngitis, sinusitis, and nasal cancer occur in many industries, indicating the prevalence of exposure to these large inhalable particles. No commercially available instrument currently exists to count and size particle sizes between 30 and 100 micrometers. This presentation describes the development of a new instrument to characterize the size distribution and concentration of inhalable aerosols (from 10 to 100 micrometers in diameter) in near-real time. A virtual portable inhalable particle spectrometer (vPIPS) relies on the principles of virtual impaction and with vertical elutriation to separate large particles as a function of aerodynamic diameter. The instrument has a diameter of 118 mm and weighs 0.5 kg. A 785 nm 100 mW laser diode and Si photodiode detector provides real-time particle counts. The instrument sizes particles from 30 to 100 micrometers into 10 micrometer size bins. Experimental sampling efficiency was tested in a calm air chamber with particle sizes from 10 to 100 micrometers. The vPIPS was capable of size-selective sampling and showed good sampling efficiencies. Fluid flow and particle transport in the sampler was also evaluated using computational fluid dynamics modeling. Experimental sampling efficiencies showed good agreement with computational and analytical solutions.