SEDL / STP / STP980-EB / STP26452S

A Technique for Dust Measurement

Goss, GR
Director, Product Technology and Research Technician, Oil-Dri Corporation of America, Chicago, IL

Reisch, FJ
Director, Product Technology and Research Technician, Oil-Dri Corporation of America, Chicago, IL

Pages: 15    Published: Jan 1989

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Abstract

The presence of dust in either pesticide formulation ingredients or the finished product is a nuisance at best. Dust in the pesticide industry is commonly measured as minus 60 mesh (250 micrometers) material. Dust itself is much smaller airborne particulate matter. A device was constructed to measure airborne particles by weight and light absorption. A sample is introduced through a port into a 0.0566 m³ space. Dust generated during the fall is measured optically and gravimetrically. Absorbance is determined with a tungsten light source, a cadmium sulfide detector and a 0.305 m path length. Dust weight is determined by evacuation of the air above the sample and collection on filter paper. Instrument performance was determined with three types of absorbent minerals, a hormite, a montmorillonite and a diatomite. Light absorption and dust weight were linear with the amount of material introduced. Though materials were slightly different colors, a linear correlation was observed in dust weight vs. absorption plots. Particles in the dust ranged from 2 to over 200 microns, averages ranging from 20 to 65 microns.