MEASUREMENT OF THE SAMPLING EFFICIENCY OF PERSONAL INHALABLE AEROSOL SAMPLERS USING A SIMPLIFIED PROTOCOL

Abstract

Traditional protocols for the performance evaluation of personal inhalable aerosol samplers utilize full-size manikins and large cross-section wind tunnels. Thus, these sampler evaluation procedures are complex, very costly, and time consuming. In addition, it is difficult to provide an adequately uniform wind velocity and aerosol concentration over large cross-section wind tunnels. A simplified test protocol, developed in our recent studies, is evaluated in this paper. The protocol is based on a three-dimensional rectangular simplified torso that simulates the dimensions of the human chest. This arrangement allows simultaneous measurement in four discrete orientations to the wind, thus providing useful orientation-dependent sampler information and possibly reducing the number of measurements needed. Sampling efficiencies of four personal inhalable aerosol samplers (the IOM, GSP, 37-mm closed-face cassette, and the button sampler) were measured using the simplified test protocol and the traditional approach for three particle sizes (7, 29, and 70 μm) in four inlet orientations to the wind (0, 90, 180, and 270°) and two wind velocities (0.5 and 2.0 m s -1). It was found that when these samplers were mounted on the simplified torso versus the full-size manikin, the sampling efficiencies responded to changes in the sampling conditions in the same way regardless of whether the samplers were mounted on the simplified torso or the full-size manikin. Also, the sampling efficiencies were found not to be statistically different when the samplers were mounted on the simplified torso versus the full-size manikin. Thus, the simplified test protocol was shown to be suitable for the performance evaluation of personal inhalable aerosol samplers.