A Multidomain Magnetic Passive Aerosol Sampler: Development and Experimental Evaluation

摘要

An innovative "quarter-sized" multidomain magnetic passive aerosol sampler (MPAS) has been developed, mainly for determining particle penetration through personal protective ensembles. The MPAS is a 28 mm disc with a height of 8.6 mm. It consists of 186 small magnets with about 140 on the collection area, arranged in an alternating N and S pole pattern. In contrast to conventional passive samplers, it uses magnetic force to collect a quantifiable amount of surrogate Fe3O4 particles within a substantially shortened sampling time. This article presents detailed design, principles of operation, performance evaluation, and the development of a deposition velocity model for the MPAS. Performance of the MPAS was evaluated under various test conditions, including different particle sizes ranging from 95 to 350 nm and wind speeds ranging from 0.48 to 1.17 m/s. A previously developed recirculation aerosol wind tunnel was employed to evaluate its performance. Experimental results show that the dimensionless deposition velocity increased with increasing particle size (e.g., about 5-fold greater for 300 nm particles than 100 nm particles at 0.48 m/s) and slightly decreased with increasing wind speeds. Our results show that this sampler is promising for the measurement of particle penetration through protective ensembles for which high collection efficiency is needed.