A particle size distribution measuring apparatus which can enhance the precision
and the reliability of measurements by eliminating the region of the particle size
having inferior measuring precision and resolution is disclosed.
In one embodiment, the particle size distribution measuring apparatus has a cell
for receiving particles, a light source section for irradiating laser lights with
a plurality of wavelengths to the cell, a detector for measuring the intensity
of a direct light passing through the cell and the scattered lights at a plurality
of scattering angles, and an arithmetic processing section which determines the
particle size distribution by using the laser light of one wavelengths for the
region of the particle size having low sensitivity at another wavelength in the
whole range of the particle size to be measured to compensate the sensitivity of
the region.
