Surface area determination by direct read-out

Claim 1

A method of determining the surface area of a solid material comprising the steps of forming a gaseous mixture of an adsorbate and a relatively nonadsorbable carrier gas in the ratio of 30 percent of the former to 70 percent of the latter, calibrating a digital counter having a digital display so as to display a selected numerical value for each unit volume of said adsorbate which corresponds to the surface area to which a monolayer of said adsorbate will adsorb at specified conditions of pressure and temperature, establishing pressure conditions to produce a continuous flow at a selected rate of flow of said gaseous mixture to measuring means controlling the display of said digital counter, flowing and continuously flowing gas mixture prior to encountering said measuring means over the surface of a sample of solid material at a selected reduced temperature at which adsorption of the adsorbate takes place to thereby cause adsorption of said adsorbate to said surface, while maintaining said continuous flow at said selected flow rate of said gaseous mixture raising the temperature of said sample of solid material to cause desorption of said adsorbate from said surface into said continuously flowing gaseous mixture to provide an additional volume of adsorbate for intermixture therewith, directing said gaseous mixture with said additional volume through a flow chamber of a correspondingly increased volume so that said previously noted selected rate of flow is substantially maintained therein by virtue of said increased volume flowing at a slower rate through said flow chamber, and causing the measurement of said continuously flowing gaseoud mixture with said additional volume of said adsorbate by operating said calibrated digital counter therewith and having said digital display of said digital counter display multiples of said selected numerical value for each unit volume of said adsorbate.

Claim 2

A method of determining the surface area of a solid material comprising the steps of forming a gaseous mixture of an adsorbate and a relatively nonadsorbable carrier gas in the ratio of 30 percent of the former to 70 percent of the latter, calibrating a digital counter having a digital display so as to display a selected numerical value for each unit volume of said adsorbate which corresponds to the surface area to which a monolayer of said adsorbate will adsorb at specified conditions of pressure and temperature, establishing pressure conditions to produce a continuous flow at a selected rate of flow of said gaseous mixture to measuring means controlling the display of said digital counter, flowing and continuously flowing gas mixture prior to encountering said measuring means over the surface of a sample of solid material at a selected reduced temperature at which adsorption of the adsorbate takes place to thereby cause adsorption of said adsorbate to said surface, while maintaining said continuous flow at said selected flow rate of said gaseous mixture raising the temperature of said sample of solid material to cause desorption of said adsorbate from said surface into said continuously flowing gaseous mixture to provide an additional volume of adsorbate for intermixture therewith, directing said gaseous mixture with said additional volume through a flow chamber of a correspondingly increased volume so that said previously noted selected rate of flow is substantially maintained therein by virtue of said increased volume flowing at a slower rate through said flow chamber, and causing the measurement of said continuously flowing gaseoud mixture with said additional volume of said adsorbate by operating said calibrated digital counter therewith and having said digital display of said digital counter display multiples of said selected numerical value for each unit volume of said adsorbate.