Characteristics and Sampling Efficiencies of MicroST Virtual Impactors
Abstract
The aerosol sampling efficiencies of two prototype MicroST virtual impactors (BigRB and LittleRB) were determined at the U.S. Army Edgewood Chemical Biological Center (ECBC). These virtual impactors are designed to be connected serially to be a two-stage aerosol concentrator. The BigRB was tested at a total air flowrate of 24.5-32.3 Lpm with a minor airflow of 2.5-3.2 Lpm. The LittleRB was tested at a total airflow of 3.2-4.9 Lpm with a minor airflow of 0.6-0.7 Lpm. Sampling efficiency tests were conducted with 0.5-, 1.0-, 2.1-, and 3.0-micrometer fluorescent PSL microspheres, and 3.9-micrometer fluorescent oleic acid particles. Previous studies show that the concentration efficiency curves of virtual impactors have an inverted "U" shape; however, this is not seen with the BigRB and LittleRB virtual impactors for the particle sizes tested. The concentration efficiency of BigRB is between 6.4 and 13.6% for particle sizes 0.5-3.9 micrometers, and the concentration efficiency of LittleRB is decreasing from 85.8 to 69.4% for particle sizes 0.5-3.0 micrometers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2006
- Accession Number
- ADA458769
Entities
People
- Deborah Schepers
- Jana S. Kesavan
Organizations
- Edgewood Chemical Biological Center