Topics in Particle and Dispersion Science

Imaging nephelometer - typically, this term is used for nephelometer designs which map the space of the observation direction of the scattered light (as represented by the scattering angle and azimuthal scattering angle pair: θ, φ; see scattering angle) onto an image plane by using a lens and/or a mirror system. In the area of the image plane where one-to-one mapping exists, each position (x, y) corresponds to an observation direction (θ, φ) of the scattered light. The image is scanned electronically (as, for example, in a CCD) yielding, through the inverse mapping, a two-dimensional scattering angle pattern. See a review and an annotated bibliography of the various nephelometer designs in, for example, Jonasz M and Fournier (2007). See also polar nephelometer.

This type of the nephelometer is most useful for studying light scattering by single nonspherical and/or inhomogeneous particles (for example, Hirst E et al 1994) because in other cases (the homogeneous sphere and dispersions of randomly oriented nonspherical/inhomogeneous particles) the angular scattering pattern tends to be axially symmetrical about the direction of the incident light, i.e. indpendent of the azimuthal angle, φ.