In the article the radiation of a gas containing macroscopic particles
and an external light beam passing the medium are described. The Prob
abilistic method of V.V. Sobolev used for solution of radiation transf
er Equations, multiple scattering of light by particles is taken into
account. The influence of scattered. particles on the radiation in spe
ctral lines and continious spectrum is investigated theoretically and
experimentally. The radiation in a closed isothermal volume containing
gas and macroscopic particles is analyses. The relations for determin
ation of gas and particles temperatures, concentrations of atoms by us
ing the measured intensities are derived. Different experimental condi
tions that differ by optical characteristics of particles and surfaces
of object are described. The possibilities of the space distributions
measurements when intensities are observed along a single line of sig
ht are discussed.