Hausner ratio

The Hausner factor is a dimensionless physical measure for the characterization of solids ( shaped to lumpy bulk materials and piles ). It is calculated as the ratio of tapped density and bulk density or as the ratio of bulk volume and tamped volume:

And is a measure of the reduction in volume by vibration or ramming.

Importance

In the technique of pharmacy, chemistry and packaging and dosing of solids which are often controlled via the volume metering accuracy depends largely on the Hausner ratio:

• Is an indicator that the volume-controlled dosing is difficult to maintain a uniform height and can be adversely affected by shocks in dosage and transport of the bulk material.
• Indicates that vibrations and shocks do not affect the volume of the bulk material, that is a higher volume-controlled metering accuracy can be achieved.