The activated charcoal is one kind of very tiny carbon granules has the very great surface area, moreover in the carbon granules also has the tinier hole - - capillary vessel. This kind of capillary vessel has the very strong adsorptive capacity, because the carbon granules surface area is very big, can therefore with the gas (impurity) the full contact. When these gas (impurity) bumps into the capillary vessel to adsorb, plays the purification. The activated charcoal surface area research is very important, the activated charcoal only then uses the result which compared to the surface area examination data the BET method examines is real reliable, domestic has many instruments only to be able at present to make the direct correlation method the examination, domestic is also eliminated now.At present domestic and foreign uses compared to the surface area test unification selects the BET law, domestic and foreign formulates the ratio surface area determination standard is take the BET test method as the foundation, please refer to our country national standards (GB/T 19587-2004) - the gas adsorption BET principle determination solid state material to compare the surface area the method. Is actually the comparison costs the time compared to the surface area examination the work, as a result of the sample adsorptive capacity's difference, some sample's test possibly needs to cost all day time, if the test procedure has not realized automates completely, that tests the personnel not to be able to leave on the time, and wants the high degree of concentration, observes the gauge board, controls the knob, will not pay attention to cause the test procedure slightly the defeat, this will waste tests personnel many valuable times.   F-Sorb 2400 are can realize the BET law measuring ability instrument truly compared to the surface area reflectoscope reflector (to have both direct correlation method), more important F-Sorb 2400 compared to the surface area reflectoscope reflector are until now the domestic only completely automated intellectualization compared to the surface area check-out facility, its test result and the international uniformity are very high, the stability is also very good, simultaneously reduces the personal error, enhances the test result accuracy.