Evaluation of the equivalency between vertical elutriators.
Pan-W; Hersh-SP; Batra-SK
Proceedings of the Sixth Cotton Dust Research Conference, beltwide cotton production research conferences, January 4, 1982, Las Vegas, Nevada. Wakelyn PJ, ed. Memphis, TN, The National Cotton Council of America, 1982 Jan; :52-57
The performance of three vertical elutriator (VE) cotton dust samplers was studied. Two VEs from the same manufacturer (VEA and VEB) were mounted in a model card room 10 inches apart. The third one (VEC) from a different manufacturer was located 10 inches from the other two. The design variables included two VEs, their position, and the test day. In the repeated Latin square design time was the variable nested within the bales which allowed the determination of the error variance. The results of the two models tested, one where the interactions were confounded and the other where the effects were treated separately, showed that the two VEs were not equivalent at the 95 percent confidence level. The differences between bales and days were highly significant, but the position was not. The results of the second analysis showed that the mean squares of the bale times position and bale times VE interactions were not significantly different. Therefore the bales were regarded as a suitable blocking variable in the repeated Latin square test. Since six out of 76 points on the the VEA versus VEB plots were outside the 25 percent range, the Occupational Safety and Health Administration (OSHA) criteria for equivalence were not met. The quantity of dust collected by VEA and VEB was 9.7 and 6.8 percent greater, respectively, than that collected by VEC. The authors conclude that the OSHA limits would be exceeded by the introduction of additional variables, such as the location of measurement, time, and instrument.
NIOSH-Grant; Cotton-dust; Sampling-equipment; Statistical-quality-control; Quality-standards; Dust-collectors; Dust-analysis
Proceedings of the Sixth Cotton Dust Research Conference, beltwide cotton production research conferences, January 4, 1982, Las Vegas, Nevada
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