ISO 18757:2003 (R2025)

ISO 18757:2003 provides guidelines for the determination of the total specific external and internal surface area of disperse or porous (pore diameter greater than 2 nm) fine ceramic materials by measuring the amount of physically adsorbed gas according to the method of Brunauer, Emmett and Teller (BET method). This International Standard only focuses on specific details relevant to fine ceramic materials. It should further be noted that the BET method cannot be applied to type I isotherms (microporous materials or chemisorption behaviour) or when the solid adsorbs the measuring gas.