The effect of multiple-scattering in measuring the radiation properties of absorbing and scattering media

Tong et al. (1983) found that the experimentally determined spectral extinction coefficients of a light-weight fiberglass insulation were 22-31 percent lower than those predicted theoretically. In connection with the desirability to obtain more accurate data, a new data-reduction method which is capable of accounting for the multiple-scattering effect is needed. A description of such a method is provided. The method is developed from a solution of the equation of transfer which governs the two-dimensional transport of radiation in a planar medium having collimated incidence. The new method makes it also possible to determine the spectral single scattering albedo, and the spectral backscattered fraction factor. The obtainable data are required in the calculation of radiative heat transfer in porous insulations.