|Hoffmann, Wesley - Clint|
|Martin, Daniel - Dan|
|Fritz, Bradley - Brad|
Submitted to: Journal of the American Mosquito Control Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/7/2007
Publication Date: 9/19/2007
Citation: Hoffmann, W.C., Walker, T.W., Martin, D.E., Barber, J.A.B., Gwinn, T., Smith, V.L., Szumlas, D., Lan, Y., Fritz, B.K. 2007. Characterization of truck-mounted atomization equipment typically used in vector control. Journal of the American Mosquito Control Association. 23(3):321-329. Interpretive Summary: Truck-mounted sprayers are the most common equipment used to apply products for the control of human disease vectors, such as mosquitoes and flies. The selection and setup of these machines significantly affects the level of control achieved during an application. The distribution of droplet sizes produced by eleven different machines was evaluated with commonly-used insecticides. As designed, the sprayers produced different droplet sizes to satisfy a range of operational needs. Good correlations were found between the spray droplet size distributions obtained from three different spray droplet measurement systems. Results from this study allow users of these sprayers to confidently select the sprayer and operational parameters that best fit their application situation.
Technical Abstract: The control of arthropods that are vectors of human and animal disease is a high priority for both public health and military officials. As droplet size is a critical factor affecting vector control applications, the droplet size spectra produced by eleven sprayers and three spray formulations were evaluated. The droplet size spectra were measured by a laser diffraction instrument, a hot wire system (AIMS probe), and rotating slides. The information presented can be used by applicators to select the sprayer that produces the droplet size spectra needed for their particular application situation. There were considerable differences in the droplet size spectra produced by the different sprayers tested. The volume median diameter (VMD) for the water-based sprays ranged from 4.7 to 211 microns depending on the sprayer, and the percent of spray volume contained in droplets less than 20 microns ranged between 0.5-98.9 percent. The VMD for the oil-based sprays ranged from 9.4 to 125.3 microns and the percent of spray volume contained in droplets less than 20 microns ranged between 2.4 - 97.9 percent. The correlations between the VMD measured by the laser system and the mass median diameter, Sauter diameter, and VMD measured by the AIMS probe were all significant. Generally, the slide VMD’s were numerically similar to the VMD’s from the laser system and the Sauter diameter from the AIMS Probe.