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Use of a differential pressure-based detector tube to measure resirable coal dust.
Volkwein-J; Vinson-R; Vanderslice-S; Page-S
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :12
The National Institute for Occupational Safety and Health has evaluated a new version of a dust sampler at the Pittsburgh Research Laboratory. This device uses an inexpensive plastic disposable detector tube to provide an immediate indication of cumulative dust exposure. A low flow rate pump draws a dust sample through a foam section and onto a treated glass fiber filter. The respirable fraction of dust is classified using the section of porous foam. The increasing pressure differential across the glass fiber filter created by dust mass accumulation is measured and correlated with respirable mass. Triplicate differential pressure measurements are compared to triplicate measurements of respirable dust mass collected using the U.S. Coal Mine Dust Personal Sampling Unit. In this unit, a Dorr-Oliver cyclone classifies the respirable fraction with subsequent filter mass measurement. Results show that the differential pressure of specific filtration media can be an effective surrogate for respirable mass. Data show that there is a dependence on coal type, an effect of relative humidity, and an effect of altitude change. These dependencies are broadly within +/-50% of the average response for all factors. There also appear to be two distinct coal type responses, perhaps related to coal rank. For specific coals the regression coefficients are better than 0.9. For general use the detector tube can be used to estimate respirable dust levels using laboratory generated calibration curves. However, calibration to a specific coal type improves accuracy to +/-25% of the gravimetrically determined mass.
Dust-samplers; Dusts; Detectors; Dust-exposure; Exposure-levels; Pumps; Filters; Respirable-dust; Coal-dust; Humidity; Altitude; Measurement-equipment; Analytical-processes
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana