QUANTITATIVE ASSESSMENT OF THE CONDITIONING OF THE INVERSION OF QUASI-ELASTIC AND STATIC LIGHT-SCATTERING DATA FOR PARTICLE-SIZE DISTRIBUTIONS

The rank of the data transfer matrices is used as a quantitative crite rion for the assessment of the degree of ill conditioning of the inver sion of static, single-angle, and multiangle quasi-elastic light scatt ering (QELS) data for particle size distributions by intensity, number , and volume. It is shown that the simultaneous (constrained) inversio n of three-angle and more angle data sets for distributions by volume can be well-conditioned. The inversion of QELS spectral data is hardly better conditioned compared to the inversion of correlation data. How ever it appears that spectral data require about 10 times slower sampl ing times in the data-collecting procedures. The inversion of static d ata for distributions by volume appears also to be well-conditioned.