An Investigation of Sample Weight Loss from Air Filter Samples. M. Pannell , P. Grogin, Los Alamos National Laboratory, Los Alamos, NM Advances in availability and affordability of lower gravimetric detection limits permit industrial hygienists to precisely measure aerosol samples, permitting closer tolerances on the levels of permissible worker exposures. However, a loss of the sample aerosol results in an underestimate of exposure concentration and may permit personal overexposure. Weight losses do occur and may permit personal exposures to hazardous materials. As sample loading increases, the weight loss increases.
Weight loss is most evident on total fraction samples.
Elimination of Desiccation of 37mm PVC Filters Used in Dust Collection. The greater precision and accuracy provided by lower gravimetric detection limits necessitates the elimination of variability found in traditional methods of gravimetric analysis. A two-phase study was conducted to assess the reliability of desiccation. In Phase I, regression equations were generated that quantified variations in 5.0 um 37mm PVC filter weight with changes in relative humidity. Correlation coefficients of filter weight variation with changes in relative humidity ranged from 0.86 to 0.93.