What is the bulk density and tap density of powder?

A. Bulk Density

The bulk density of the powder refers to the free flow of powder into the standard container (measuring cup) under the limited conditions, 

then the powder quality of the unit volume is measured and measured in g/ 3.

B. Tap density

 When the powder is left in the standard container, the arch bridge is formed due to the friction between particles.
If the powder is subjected to vibration in a limited condition, the mass of the unit volume measured by the collapse of the arch bridge is called 

the vibration density of the powder.