ASTM D3663-25

Annotation of standard text ASTM D3663-25 :

This test method establishes the standard procedure for determining the surface areas of catalyst and catalyst carriers that have Type II or IV nitrogen adsorption isotherms, and specified minimum area. A volumetric measuring system is used to obtain at least four data points which fit on the linear BET line. The surface area of a catalyst or catalyst carrier is determined by measuring the volume of nitrogen gas adsorbed at various low-pressure levels by the catalyst sample. Pressure differentials caused by introducing the catalyst surface area to a fixed volume of nitrogen in the test apparatus are measured and used to calculate BET surface area.


Keywords:
catalyst, nitrogen adsorption, surface area,, ICS Number Code 71.040.30 (Chemical reagents)