Specific surface measurement

The specific surface of a sample is the ratio between its real surface and its mass. The real surface differs from the apparent surface of a sample by taking into account the surfaces of each pore which communicate with the exterior. It is often expressed in m2/g.

This quantity is often used to characterize phenomena occurring at the interfaces of powders or solid foams: adsorption, catalysis, etc.

The BET method makes it possible to quantify and characterize the specific surface of porous samples in an efficient way

Florian Rodrigues, R&D Project Manager, Calnesis

Surface area measurement method

The specific surface is most often measured by the BET method (Brunauer, Emmett and Teller). This technique consists in measuring the quantity of gas necessary for the formation of a gaseous mono-layer around each sample particle to determine its real surface.