A simple apparatus for the measurement of single component adsorption of liquid vapors on solid adsorbents/catalysts is described. The intracrystalline sorption capacity for liquid n-hexane of silicalite-I measured using the apparatus is in good agreement with that reported earlier. Adsorption isotherm data for the sorption of n-hexane on silicalite and water on NaM were collected using the apparatus. This apparatus provides reliable and accurate adsorption isotherm data for the sorption of Liquid vapors on a large and hence representative sample of solid catalysts and absorbents by gravimetric method, and it does not require a high-vacuum system: