National Aerospace Laboratory of Science Technology Agency

Hideo Nagasu and Tohnichi Computer Applications Co., Ltd.

Shigeru Hayashi

Shoji Horiuchi

Tadashi Takahashi

Takasui Saito

The invention relates to a method and an apparatus for determining the size or the size distribution of fine particles. A single particle or a group of particles are shone by a parallel polarized beam of a single wave length and the scattered intensity on the plane of polarization of the incident beam is measured by a photodetecting array. For a single particle the size is determined from the peak scattering angle at which the profile of the product of the scattered intensity and the scattering angle has the peak. On the other hand, for a group of particles, the size distribution is determined from the angular variation of the scattered intensity or the profile of the product of the scattered intensity and the scattering angle measured on the plane of polarization of the incident beam. For fine particles mixed with large particles the scattered intensities on the plane at a right angle to the plane of polarization measured by another photodetecting array is used to improve the accuracy of size determination of the fine particles.

Method and apparatus for measuring the size of a single fine particle

A photoelectric conversion sensor for measuring particle size or size distribution based on the light scattering phenomena with excellent precision and higher resolving power. The sensor is characterized in that 8 or more arcuate photoelectric conversion elements each being defined by two concentric arcs with different radii and two adjacent elements in the radial direction are so arranged that the gaps in the radial direction between two adjacent elements in the radial direction can be substantially eliminated by shifting them in the circumferential direction.

Growing community of inventors

Chofu, Japan

Shigeru Hayashi