Particle size distribution measurement device, particle diameter distribution measurement method, and particle diameter distribution measurement program

A particle size distribution measurement method using a particle size distribution measurement device having an imaging unit configured to image particles in a cell, and an analysis unit configured to calculate a particle size distribution by calculating a diffusion velocity due to Brownian motion of the particles based on imaging data obtained by the imaging unit, the method comprising:

• a data group acquisition step for acquiring an imaging data group including a plurality of pieces of imaging data obtained by the imaging unit at each of a plurality of focus positions in the cell;
• a variation value calculation step for calculating a variation value of a predetermined evaluation parameter obtained from each of the plurality of pieces of imaging data included in the imaging data group;
• and
• a focus position determination step for determining a measurement focus position used at a time of measurement based on the variation value corresponding to each of the plurality of focus positions.

A non-transitory computer readable medium storing a particle size distribution measurement program used for a particle size distribution measurement device having an imaging unit configured to image particles in a cell, and an analysis unit configured to calculate a particle size distribution by calculating a diffusion velocity due to Brownian motion of the particles based on imaging data obtained by the imaging unit, wherein the program causes a computer to carry out functions as:

• a data group acquisition unit configured to acquire an imaging data group including a plurality of pieces of imaging data obtained by the imaging unit at each of a plurality of focus positions in the cell;
• a variation value calculation unit configured to calculate a variation value of a predetermined evaluation parameter obtained from each of the plurality of pieces of imaging data included in the imaging data group;
• and
• a focus position determination unit configured to determine a measurement focus position used at a time of measurement based on the variation value corresponding to each of the plurality of focus positions.