Centrifugal sedimentation-type particle diameter distribution measurement device

A centrifugal sedimentation-type particle diameter distribution measurement device comprising:

• a cell holding body configured to hold a measurement cell housing a measurement sample and a dispersion medium;
• a cell protecting member interposed between the cell holding body and the measurement cell and configured to disperse centrifugal force applied to the measurement cell to prevent breakage of the measurement cell, the cell protecting member having a concave part;
• a cover attached to the cell holding body so as to cover the at least a portion of the concave part of the cell protecting member and prevent the measurement cell from being detached from the cell holding body;
• a rotation section configured to rotate the cell holding body and apply centrifugal force to the measurement cell, wherein the cell protecting member is configured to not contact the cover and move radially outward when receiving the centrifugal force during rotation of the cell holding body;
• a light source provided on one side of a rotation passage region of the measurement cell and configured to irradiate the cell with light;
• a photodetector provided on another side of the rotation passage region of the measurement cell and configured to detect light transmitted through the cell;
• and
• a particle diameter distribution arithmetic section configured to acquire a light intensity signal from the photodetector and calculate a particle diameter distribution,
• wherein a distance from a rotation center of the rotation section to an outer peripheral edge of the cover is configured to be smaller than a distance from the rotation center of the rotation section to the optical path of the light.