Hemispherical transmittance determination of spectral radiative properties of the slab-like scattering specimen by moisture content variation

The matter of the article is the transmission of radiation by the scattering and absorbing slab-shaped media. Spectral absorption and scattering coefficients (k,σ) have been determined from the hemispherical transmittance by minimizing the squared sum of differences E2 between the measured -logT and the calculated one according to equations of the developed model. The model starting point is the two-flux theory. Existence of analytical solutions for the two-flux transmittance allowed simple spectra treatment needed for inclusion of matrix algebra into E2-minimization. Spectra of cellulose sheets were measured in the 1.30-2.19μm range with the varied content of adsorbed water in the range from 0 to 0.227. Set of 20 k,σ coefficients corresponding to 20 water content values, and separate spectral absorption coefficients of cellulose and water were the output of the spectral error minimization.