Dynamic measurements of soot aggregate size in diesel exhaust by a light scattering method

A light scattering method based on the Rayleigh-Debye approach quantifying the angular scattering from poly-disperse aggregates was tested in an attempt to measure the mean radius of gyration of diesel soot aggregates in diesel exhaust. The aggregate size measured by this method under steady operating conditions showed qualitative agreement with the mode peak mobility diameter obtained by the scanning mobility particle sizer. After the assessment, the method was applied to measure the temporal variation of the mean radius of gyration of diesel soot aggregates under transient mode operation.