Particle size analyzer based on laser diffraction method

A particle size analyzer based on laser diffraction method, comprising:

• an irradiation optical system for irradiating laser beam to particles, said irradiation optical system having a semiconductor laser in an output beam wavelength of about 300 to about 400 nm as a light source;
• a measurement optical system situated near the irradiation optical system for measuring a space intensity distribution by receiving light diffracted/scattered by particles of the laser beam from the irradiation optical system, said measurement optical system including a plurality of light sensors disposed in an area of a predetermined front angle in an irradiating direction of the laser beam, a converging lens for converging light diffracted/scattered by a particle group to be measured, and a ring detector disposed at a focal position of the converging lens and formed of a plurality of independent conical light receiving surfaces in a shape of a ring, half ring or ¼ ring having different radii;
• and
• an operation portion connected to the measurement optical system for obtaining a particle size distribution of the particles from results measured by the measurement optical system.