摘要 |
PURPOSE:To measure light intensity distribution within an all scattered angle range to measure the particle diameter of a fine particle, by a method wherein laser beam is converted to parallel beam by a collimator lens system and scattered light from a specimen is measured by an optical fiber and a photodetector. CONSTITUTION:A specimen 8 is irradiated with parallel beam 3 molded by laser 1 and a collimator lens system and scattered light is guided to a photodetector 12 by an optical fiber 10 arranged in a scattering angle direction desiring the measurement of scattered light. A microlens 9 is arranged in front of the optical fiber in order to guide the parallel beam to the scattering angle direction and a filter is arranged in front of the photodetector 12 in order to remove external stray light. A plurality of optical fibers as mentioned above are arranged to measure scattered light intensity distribution which is, in turn, converted to particle size distribution by a scattered light intensity distribution-particle size distribution converting apparatus 7. By this method, even a fine particle low in the change of the scattered light intensity distribution can be measured. |