Particles distribution functions were reconstructed on the basis of analysis more than 100 experimental aerosol particles distribution functions along the flow pass on different stages of technological process by the aerodynamic classification. Applying integral methods of diagnostic radiation wavelengths and the scattering angles which are more sensitive to the particles sizes spectra changes were estimated. Thereby, the initial parameters of aerosol lidar construction with the diode lasers were obtained. The range of the industrial aerosols spectra size changing were estimated and it is possible to solve the inverse task on the selected radiation wavelengths.