Gravitational particle size analyzer

Supervisor: Guia Guarini

The gravitational particle size analyzer allows to measure the particle size distribution of micrometric powders dispersed in water or other solvents.

Principle of operation

The particle size distribution of the powders is obtained by exploiting the sedimentation velocity of the dispersed particles in the liquid medium on the basis of the Stokes’ law. The concentration of the different sizes is found by the attenuation of a X-ray beam crossing the cell containing the sample.  During the sedimentation the cell is scanned by the X-ray beam by moving downward the cell itself with the velocities corresponding, on the basis of the Stokes’ law, to the differsent sizes in order to make faster the determination of the finer fractions that otherwise would take long times.

Micromeritics SediGraph III Plus

• Size range: 0.1-300 µm (typically 0.18-100 µm).
• Sample volume: 50 mL
• Input data: density and viscosity of the dispersing liquid and density of the powders.