| Popis: |
A methodology for evaluating the collection efficiency (CE) of airborne spray flux samplers in a low speed spray dispersion tunnel was developed and evaluated. Prior to evaluation of the testing protocol, dispersion tunnel operating characteristics were examined. Air speeds and flux measurements in the working section of the tunnel showed defined gradients which the collection efficiency protocol had to address. The proposed methodology used soda straws and monofilament line as spray flux samplers because their theoretical CE could be calculated to estimate the actual spray flux measured across a sampler of interest. This estimated actual flux was then used to determine the experimental collection efficiency of this sampler. This protocol was tested by comparing the theoretically and experimentally derived CE of soda straw collectors. Results showed no statistical difference between the theoretical and experimental CE at each air speed tested. As the air speeds increased from 0.45 to 4.0 m/sec, the CE for the monofilament line increased from 52.3% to 82.6%, respectively, while the CE of the soda straw also increased from 6.7% to 45%, respectively. This methodology might be used to determine CE for various spray flux samplers, such as flat plate collectors, rotating rods, and screens. |
