Optical diagnostics developed for the investigation of liquid mixtures properties onboard the International Space Station. The SODI facility for the MSG is a 2-wavelength Mach Zehnder Interferometer set-up and a thermal conditioner for liquid cells. It is designed to enable measurements diffusion coefficients in liquid mixtures, primarily crude oils. Thermodiffusion (Soret) coefficients will be measured by applying a thermal gradient to the cell; when relaxing the temperature gradient, one can then also measure isothermal diffusion.
The set-up is designed to enable exchange of the cell in the conditioner and thereby, other experiments that can make use of the capabilities. The design will enable to mount the cell conditioner on a system generating low frequency vibrations so as to quantify their influence on the diffusion process. The facility has been used for experiments DCMIX1 (Diffusion Coefficient in Mixtures), IVIDIL (Influence of VIbration stimuli on DIffusion in Liquids), Colloid (Aggregation of colloidal suspensions), DCMIX2, DCMIX3, Colloid2, DCMIX4.