Standard argon adsorption data at 77 and 87 K are presented for two proposed reference carbons, one nongraphitized and the other graphitized. Surface properties of the reference carbon,, are analyzed on the basis of low-pressure adsorption data. The usefulness of the reference adsorption isotherms reported in this work was illustrated for the cc, plot analysis of surface properties of graphitized carbons, as well as for the determination of the external Surface area and micropore volume of activated carbons. The information derived from the analysis of argon adsorption data at both 87 and 77 K was in a good agreement with earlier results obtained from nitrogen adsorption isotherms at 77 K.