Accuracy Criteria Recommended for the Certification of Gravimetric Coal Mine Dust Samplers

摘要

Procedures for testing bias and precision of gravimetric coal mine dust sampling units are reviewed. Performance criteria for NIOSH certification of personal coal mine dust samplers are considered. The NIOSH criterion is an accuracy of 25 percent at the 95 percent confidence interval. Size distributions of coal mine dust are discussed. Methods for determining size distributions are described. Sampling and sizing methods are considered. Cyclone parameter estimation is discussed. Bias computations for general sampling units are noted. Recommended procedures for evaluating bias and precision of gravimetric coal mine dust personal samplers are given. The authors conclude that when cyclones are operated at lower rates, the NIOSH accuracy criteria can be met.