本文件规定了通过根据Brunauer、Emmett和Teller方法测量物理吸附气体的量，根据2015年国际纯粹与应用化学联合会（IUPAC）建议，测定分散（例如纳米粉末）或多孔固体的总比表面积和内表面积。 注意对于表现出化学非均相表面的固体，例如金属载体催化剂，BET法给出了总表面积，而表面积的金属部分可以通过化学吸附法测量。

This document specifies the determination of the overall specific external and internal surface area of either disperse (e.g. nano-powders) or porous, solids by measuring the amount of physically adsorbed gas according to the method of Brunauer, Emmett and Teller method,^[1] based on the 2015 International Union for Pure and Applied Chemistry (IUPAC) recommendations^[3]. NOTE       For solids exhibiting a chemically heterogeneous surface, for example, metal-carrying catalyst, the BET method gives the overall surface area, whereas the metallic portion of the surface area can be measured by chemisorption methods.