'Concentration' displayed in particle size distribution measurement usually indicates the intensity of the received light signals, which is related to the number of particles, usually called 'optical concentration' instead of 'percentage concentration'. For laser particle sizing
, the more particles in the suspension, the higher the optical concentration. However, when there are too many particles in the suspension, the optical density will be reduced if the light is overscreened.
For the sedimentation method, the more particles in the suspension, the lower the optical concentration.