Calibration of light‐scattering instruments: A critical survey

Abstract A survey of the literature on the calibration of light scattering instruments has been made, including an extensive bibliography. The values of the Rayleigh ratio R 90 and depolarization ρ μ for benzene, toluene, carbon tetrachloride, and carbon disulfide and the excess turbidity of Cornell polystyrene and D.C./P.J.3 polystyrene (0.5% solutions in toluene) were tabulated for two wavelengths (4358 and 5461 A.). Examination of these results showed a larger variation in reported values than is generally assumed acceptable (only so‐called “high” values have been considered). No correlation was found with the various standards used for the original calibration. Some aspects of the most usual methods of calibration are discussed and arguments are considered which would favor those values of R 90 (or excess turbidity) that are at the lower limits of the range reported (but still in the region of “high” values). The difficulty of using Einstein's equation in determining the exact values of R 90 is pointed out.