title: Cotton dust sampling, III-estimation of statistical errors with vertical elutriators.
abstract: Cotton dust levels measured by vertical elutriators have been studied in terms of the variance components associated with statistical errors due to sampling equipment, location, time and repeated sampling. A thumb-rule is proposed for estimating sampling errors of three-hour vertical elutriator samples as a function of average dust level. Relative efficiency of three-hour samples is shown to be superior to that of six-hour samples at moderate dust levels (0.4-0.6 mg/m3) but inferior at low dust levels (0.1-0.2 mg/m3. Errors due to location and equipment are found insignificant from this particular study.
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000032:analysis*; D004391:Dust / Q000032:analysis*; D003368:Gossypium; D009787:Occupational Medicine / Q000295:instrumentation*; D013223:Statistics as Topic; D013783:Textile Industry; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D000395:Air Pollutants, Occupational; D004391:Dust