Proposed on the basis of a closed duct to the stimulus stream to create air flow with a wide range of particle sizes. This is achieved by pulsed injection of the test powder flow and subsequent relaxation recession concentration of aerosol particles. Concentration accompanied by a monotonic decline offset range of particle sizes in the range of small sizes. Performed a series of measurements of flow aerodisperse gravimetric method and integral methods of laser sensing (integrated light scattering and spectral transmission) and to estimate the error of these dimensions. Thus, it is shown that the pulse injection of aerosols into the air stream and the subsequent decline in the concentration and dispersion of the change can be used to model flow aerodisperse.