How to measure the specific surface area (BET)?

The specific surface area is a number that characterizes the surface area of solids, especially porous solids. Expressed in surface area per unit mass, the SI unit is m²/g. Commonly used in adsorbents, catalysts, desulfurizers, dehydrants, additives, fillers, aerospace materials, etc., the specific surface area of different solids varies greatly, such as the specific surface area of metal powder is small, generally in 0.2-5m²/g, and the specific surface area of super activated carbon can reach 2000-3000m²/g.

Specific surface area analysis with specific surface area and aperture analyzer SSA4000 or physical adsorption instrument SSA7000, usually first take 0.1-10g material, first vacuum heating treatment, then weigh the dry weight of the sample, and finally test on the instrument. The specific surface area can be calculated by the adsorption isotherm of the sample adsorbed nitrogen measured at 77K. The BET test principle can be referred to the standard "ISO9277 Gas Adsorption BET Method for the Determination of the specific surface area of solid substances".

SSA-4000 Specific surface area&Pore size analyzer

SSA-7000 Automatic gas adsorption analyzer