BS ISO 9277:2010

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviated terms
5 Principle
6 Procedure
7 Evaluation of adsorption data
8 Test report
9 Use of reference materials
Annex A (informative) - Cross-sectional areas of some
        frequently used adsorptives
Annex B (informative) - Certified reference materials for
        the BET method
Annex C (informative) - Surface area of microporous
        materials
Bibliography

Describes the determination of the overall specific external and internal surface area of disperse (e.g. nano-powders) or porous solids by measuring the amount of physically adsorbed gas according to the Brunauer, Emmett and Teller (BET) method.

This International Standard specifies the determination of the overall (see Note) specific external and internal surface area of disperse (e.g. nano-powders) or porous solids by measuring the amount of physically adsorbed gas according to the Brunauer, Emmett and Teller (BET) method (see Reference [1]). It takes account of the International Union for Pure and Applied Chemistry (IUPAC) recommendations of 1984 and 1994 (see References [7][8]).

NOTE For solids exhibiting a chemically heterogeneous surface, e.g. metal-carrying catalysts, the BET method gives the overall surface area, whereas the metallic portion of the surface area can be measured by chemisorption methods.

The BET method is applicable only to adsorption isotherms of typeII (disperse, nonporous or macroporous solids) and typeIV (mesoporous solids, pore diameter between 2nm and 50nm). Inaccessible pores are not detected. The BET method cannot reliably be applied to solids which absorb the measuring gas.

A strategy for specific surface area determination of microporous materials (typeI isotherms) is described in AnnexC.