This part specifies the principle, apparatus, preparation, procedures, calculation of results and the like for the determination of protection time of granular activated carbon from coal against benzene and chloroethane vapors under specified conditions.
This part is applicable to the determination of protection time of granular activated carbon from coal against benzene and chloroethane vapors, and also to impregnated activated carbon.
2 Normative references
The following documents contain provisions which, through reference in this part of GB/T 7702, constitute provisions of this part. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest editions apply to this part.
GB/T 690-1992 Chemical reagent — Benzene (neq ISO 6353-3:1987 R 48)
WJ 2281 Verification regulation of flowmeters for protective equipment tests
WJ 2285 Verification regulation of measuring tubes for activated carbon and impregnated activated carbon tests
3 Terms and definitions
For the purposes of this part of GB/T 7702, the following terms and definitions apply.
3.1
protection time against benzene vapor
time from the inflow of an air flow containing benzene vapor to the benzene vapor permeating the activated carbon layer under the specified test conditions
3.2
protection time against chloroethane vapor
time from the inflow of an air flow containing chloroethane vapor to the chloroethane vapor permeating the activated carbon layer under the specified test conditions
4 Principle
4.1 Determination principle of protection time against benzene vapor
