Senior Associate, Continuum Dynamics, Inc., Ewing, NJ
Specialist, Stewart Agricultural Research Services, Inc., Macon, MO
Principal Scientist, NCASI West Coast Regional Center, Corvallis, OR
Pages: 15 Published: Jan 2003
The ASTM Standard: Standard Test Method for Particle Size Distribution of Granular Carriers and Granular Pesticides (E726-01) is the only ASTM standard that specifically addresses the characterization of nonspherical particles. To our knowledge there is no standard for particle size distribution measurements by laser diffraction or for particle sphericity measurements by any means to complete the description of the granular material. The present paper reviews a modeling effort that effectively characterizes and then represents the behavior of nonspherical particles during aerial application, highlights the difficulties inherent in interpreting light scattering by nonspherical particles, and suggests a laboratory experiment that accurately recovers particle sphericity. Model revisions enable the user to select the granular application technique from a menu of options once the granular material has been adequately parameterized. Quantitative comparisons are made with available field data to demonstrate the implementation of the several available granular material delivery systems. Notice is made that a standard should be developed for measuring (1) particle size distributions using laser diffraction instruments, and (2) particle sphericity with a technique suggested in the paper.
Granular material, particle size distribution, particle sphericity
Paper ID: STP11207S