[Methods and equipment for two-stage gravimetric measurements of dust levels]

The two stage gravimetric technique used for the measurements of industrial aerosols, in combination with measurements of mass-related concentrations of particles in the air, provided major hygienic information on the sizes (dispersity) of the inhaled particles. The results of the measurements taken in various branches of industry, ore and alluval deposit mines clarified the fundamental properties of the particles' distribution into rough and thin fractions. An express two-stage gravimetric technique for determining ore aerosol dispersal contents was proposed, along with the technical characteristics of the USSR-produced dust counters.