Patent ID: 8107074

Claim:
An analytical method for an optical measurement method, comprising: using an apparatus which includes: a container for storing a liquid or gel sample in which particles are dispersed movably in a medium; a power source for generating a voltage with a given pattern including DC, frequency modulation, and voltage modulation, or a pattern arbitrarily set; an electrode pair disposed in the container, and adapted to be applied with the voltage from the power source to generate a electric field distribution arranged regularly in the container; control means for controlling the application of the voltage from the power source to the electrode pair to control the generation and annihilation of a diffraction grating resulting from the density distribution of particles generated from a migrating force acting on the particles in the sample in the container; a light source for applying light to a portion of the container where the diffraction grating is generated; and a light detector for detecting diffracted light of the light generated by the diffraction grating; and analyzing the size of the particles in the sample from the temporal change of diffracted light intensity detected by the light detector, wherein in the particle size analysis, the size distribution of the particles is obtained based on the temporal data of the square root of the diffracted light intensity sequentially detected.