| 摘要 |
PURPOSE:To expands a measurable range of particle size by composing a converging means for sideward scattered light of a condenser lens which is provided at right angles to a laser beam and has its focus in a detection area, and setting its angle of convergence to at least 45 deg.. CONSTITUTION:Sideward scattered light 2' generated when a particle crosses the laser beam 2 at a scattering point 3 is converged by the condenser lens 4 provided at right angles to the laser beam 2 and detected by a detector 7. In this invention, the convergence angle xsi of said sideward scattered light 2' is set to >=45 deg.. Consequently, the condenser lens 4 has an at least 45 deg. angle xsi of convergence, so oscillation components of integral scattering cross section of about 0.4-1mum in particle side are reduced greatly. Consequently, the measurable range of particle size is expanded. |
