Question

Air permeability method for determining surface area

Answer 1

Explanation:

The specific surface is derived from the resistance to flow of air (or some other gas) through a porous bed of the powder.

...

Other fields where air permeability has been used to determine specific surface area include:

Paint and pigments.

Pharmaceuticals.

Metallurgical powders, including sintered metal filters.

hope you get it now....

Answer 2

Explanation:

The specific surface is derived from the resistance to flow of air (or some other gas) through a porous bed of the powder.

...

Other fields where air permeability has been used to determine specific surface area include:

Paint and pigments.

Pharmaceuticals.

Metallurgical powders, including sintered metal filters.