Gravimetric Measurement of the Molecular Area of Some Adsorbed Gases

A modified Gravimat, which is a sorption apparatus that includes the Gast microbalance, has been used to measure sorption isotherms of nitrogen, krypton, methane, propane, and 2,2-dimethylpropane on glass, gold, aluminum, and polytetrafluoroethylene (PTFE). Cross-sectional areas of the adsorbates derived from the Isotherms on the basis of the BET theory are compared for the different adsorbents.