Measurement of air velocity in mines.

The Bureau of Mines investigation addressed two primary issues of air velocity measurement in mines: the determination and use of correction factors, and the development of guidelines for the selection of a suitable site at which the measurments should be taken. Other facets of the investigation included a comparison of measurement methods and devices, and air course cross sectional area measurement. The study consisted of theoretical, laboratory, and in-mine investigations. The measuremnt devices included in the experimental phase were vane anemometer, vortex shedding anemometer, a prototype thermoanemometer, smoke tube, and oil of wintergreen sprayer. The measurement methods included single point centreline, timed point traverse, continuous traverse for the anemometers, and various distances and cloud positions for the smoke tube and oil of wintergreen devices. (A)