IS 8425 : 1977 Code of practice for determination of specific surface area of powders by air permeability method

1 Scope

1.1 This standard describes the following methods for thedetermination of specific surface area of powders. These methodsare applicable to powders whose surface areas lie within the rangeof 500 to 40 000 cm²g:

a) Constant flow type air permeability method (Lea and NurseType),

b) Variable flow type air permeability method (Blaine Type), and

c) Variable flow type air permeability method (Rigden Type).

1.2 The methods described in 1.1 differ basically in the way inwhich the flow resistance is measured.

2 References

IS 4879 : 1968Method of sub-division of gross sample of powder usedfor determination of particle size

IS 5516 : 1969Specification for variable flow type air-permeabilityapparatus (Blaine type)

IS 5536 : 1969Specification for constant flow type air-permeabilityapparatus (Lea and Nurse type)