Optical measurement method and optical measurement device

An optical measurement method of a dispersion liquid containing particles, the method comprising:

• an acquisition step of acquiring a plurality of images of the particles obtained by causing incident light to be incident on the dispersion liquid with a changed intensity, continuously in time for each intensity of the incident light;
• a measurement step of measuring a moving average distance of the particles for each intensity of the incident light from the plurality of images acquired continuously in time for each intensity of the incident light obtained by the acquisition step;
• and
• a calculation step of calculating an apparent particle size distribution for each intensity of the incident light from the moving average distance of the particles for each intensity of the incident light obtained by the measurement step, to obtain a true particle size distribution from the apparent particle size distribution for each intensity of the incident light.

An optical measurement method of a dispersion liquid containing particles, the method comprising:

• an acquisition step of acquiring a plurality of images of the particles obtained by causing incident light to be incident on the dispersion liquid with a changed intensity, continuously in time for each intensity of the incident light for each intensity of the incident light;
• a measurement step of measuring a moving average distance of the particles for each intensity of the incident light, from the plurality of images acquired continuously in time for each intensity of the incident light the plurality of images being obtained in the acquisition step;
• and
• a calculation step of calculating a diffusion coefficient for each intensity of the incident light from the moving average distance of the particles for each intensity of the incident light, obtained in the measurement step, to obtain a diffusion coefficient at a zero intensity of the incident light from the diffusion coefficient for each intensity of the incident light, and to obtain a true particle diameter of the particles from the diffusion coefficient at the zero intensity of the incident light.

An optical measurement device for a dispersion liquid containing particles, the optical measurement device comprising:

• a light source that causes incident light to be incident on the dispersion liquid with a changed intensity;
• an image acquisition unit that acquires a plurality of images of the particles obtained by causing the incident light to be incident on the dispersion liquid with the changed intensity, continuously in time for each intensity of the incident light;
• a measurement unit that measures a moving average distance of the particles for each intensity of the incident light from the plurality of images acquired continuously in time for each intensity of the incident light obtained by the image acquisition unit;
• and
• a calculation unit that calculates an apparent particle diameter of the particles for each intensity of the incident light from the moving average distance of the particles for each intensity of the incident light obtained by the measurement unit, and obtains a true particle diameter of the particles from the apparent particle diameter of the particles for each intensity of the incident light.

An optical measurement device for a dispersion liquid containing particles, the optical measurement device comprising:

• a light source that causes incident light to be incident into the dispersion liquid with a changed intensity;
• an image acquisition unit that acquires a plurality of images of the particles obtained by causing the incident light to be incident on the dispersion liquid with the changed intensity, continuously in time for each intensity of the incident light;
• a measurement unit that measures a moving average distance of the particles for each intensity of the incident light from the plurality of images that are temporally continuously acquired for each intensity of the incident light obtained by the image acquisition unit;
• and
• a calculation unit that calculates an apparent particle size distribution for each intensity of the incident light from the moving average distance of the particles for each intensity of the incident light obtained by the measurement unit, and obtains a true particle size distribution from the apparent particle size distribution for each intensity of the incident light.

An optical measurement device for a dispersion liquid containing particles, the device comprising:

• a light source that causes incident light to be incident into the dispersion liquid with a changed intensity;
• an image acquisition unit that acquires a plurality of images of the particles obtained by causing the incident light to be incident on the dispersion liquid with the changed intensity, continuously in time for each intensity of the incident light;
• a measurement unit that measures a moving average distance of the particles for each intensity of the incident light from the plurality of images acquired continuously in time for each intensity of the incident light obtained by the image acquisition unit;
• and
• a calculation unit that calculates a diffusion coefficient for each intensity of the incident light from the moving average distance of the particles for each intensity of the incident light obtained by the measurement unit, obtains a diffusion coefficient at a zero intensity of the incident light from the diffusion coefficient for each intensity of the incident light, and obtains a true particle diameter of the particles from the diffusion coefficient at the zero intensity of the incident light.