An evaluation was made of the performance of the coal mine dust personal sampler, also called the respirable mass sampler. The quantitative effect of pump pulsating flow, particle charge, mass loading, and sampler orientation was determined. The investigation singularly involved the characteristics of the 10 millimeter cyclone portion of the sampler. The evaluation of the cyclone included obtaining penetration curves using monodisperse aerosols of several diameters for three sampling flow rates and three levels of pulsation at each rate. Polydisperse coal dust was used to evaluate the effects of particle charge, sampler orientation, air velocity, and mass loading. For application to coal mine dust, the best operating mode of the 10 millimeter cyclone would be 1.4 liters per minute at 0.3 pulsation. For application to other pneumoconiosis producing dust the best operating mode of the 10 millimeter cyclone is 1.7 liters per minute, zero pulsation.