Abstract
This article concerns an investigation of the performance of the MRE 113A gravimetric respirable dust sampler to assess how well it conforms to new International Standards Organisation/Comité Européen de Normalisation (ISO/CEN) respirable dust conventions. The sampler, which is a static (or area) instrument, is used routinely for the statutory determination of the exposures of workers to respirable dust in British coal mines.
The work described here comprises two main parts: 1) a review of previous work to determine the overall sampling performance of the sampler; and 2) a description and presentation of the results from a test program, carried out in controlled conditions in a wind tunnel, to determine the overall sampling performance in moving air.
The findings from the review demonstrated the lack of systematic information on the overall sampling performance of the MRE sampler in moving air and therefore, the need for further work. The results of the experiments in moving air showed that the performance of the MRE sampler, while consistent both for small and large particles, varied with wind speed for intermediate-sized particles of aerodynamic diameters between 3 and 6 μm. These results affected the resultant size-selection curve such that, for wind speeds of 0.25 m/s, the d50 was 5 μm, which is close to the old British Medical Research Council respirable dust convention. For wind speeds of 5 m/s, the d50 was 4.3 μm, which is close to the new ISO/CEN convention. For wind speeds of 2 m/s, the d50 was higher at 5.7 μm. Final conclusions from the results await further statistical analysis. Mark, D.; Lyons, C.P.; Upton, S.L.: Performance Testing of the Respirable Dust Sampler Used in British Coal Mines. Appl. Occup. Environ. Hyg. 8(4):370-380; 1993.