A series of experiments were performed, aimed at investigation of the specific manner of formation of the mixed composition smokes from several separate sources of thermal decomposition of different wooden materials. It is shown that for adequate prediction of optical properties of the smoke aerosol it is necessary to take into account not only complex inhomogeneous structure of the disperse composition (the smoke particle size distribution density s(r, but variations of the complex refractive index m = n - ic in the size spectrum of smoke particle as well. When mixing the products of thermal decomposition of forest combustible materials, the smokes are generated which consist of mainly two separate aerosol components with different sizes: the finely dispersed one (with a size of < 250 nm) with imaginary part of the complex refractive index c~ 0,1ё0.25, and the moderately dispersed one (> 300 nm) with imaginary part c~ 0,005ё0,08. It is shown that the increase of the mean effective values of the components of CRI in the size ranges is the consequence not of external mixing of the disperse components, but the penetration of the finely dispersed absorbing component into the structure of particles of other sizes.
mixed smokes, refractive index, particle size distributions