2006 Volume 72 Issue 715 Pages 715-722
The Soret forced Rayleigh scattering method (S-FRSM) for measurement of mass diffusion coefficient has been developed. In the present paper, the theoretical analysis of the systematic effects of the experimental setup is discussed. It includes the analysis of : (1) effect of dye, (2) effect of sample thickness, (3) effect of Gaussian beam intensity distribution and (4) effect of heating duration time. The analysis of three-dimensional diffusion equation which takes into account the practical experimental conditions has clarified the influence quantity of the inadequate experimental settings. According to the present analysis, it has been found that the difference of diffusion coefficient can be negligible by employing the appropriate setting of experimental parameters. As a result of these considerations, the reliable optimization method of the measuring conditions in S-FRSM can be provided.