Studies of diesel particulate measurement techniques to be used with ventilation control strategies in underground coal mines were described. The studies were conducted as part of a joint NIOSH and Bureau of Mines project to determine the feasibility of developing a quantitative technique to separate diesel particles from coal mine dust and to evaluate its application in ventilation control strategies in underground coal mines using diesel equipment. Two gravimetric inertial sampling instruments, a personal impactor and a 10 millimeter nylon cyclone, were tested at coal mines in Utah and Illinois. The results were compared with those obtained by a light scattering instrument. The concentrations of particles with diameters below 1 micron, which represented the diesel particulate fraction, and of nitrogen-dioxide (10102440), nitric-oxide (10102439), carbon-monoxide (630080), and carbon-dioxide (124389) were measured. All measured concentrations were below their relevant NIOSH recommended limits. Representative data from the Utah mine indicated average diesel particle concentrations of (ppm), nitric-oxide concentrations of 2.99ppm, carbon-monoxide concentrations of 7.80ppm, and carbon-dioxide concentrations of 610ppm occurring during a transfer operation. The correlations between the diesel particle fraction and the nitrogen-dioxide, nitric-oxide, carbon-monoxide, and carbon-dioxide concentrations obtained by the various sampling methods were good. The authors conclude that gravimetric inertial sampling techniques can be used to separate diesel particles from coal mine dust.