采用干燥器醇法测定γ-氧化铝(平均孔径30～60×10~(-10)米)的比表面积,测定数据准确、可靠。但是,使用干燥器醇法测定X-氧化铝(干燥剂用,平均孔径15～25×10~(-10)米)的比表面积时,测定的数据比静态BET法偏高,其原因是:①X-氧化铝的细孔半径较小,容易使乙醇分子产生毛细凝聚;② The specific surface area of ​​γ-alumina (average pore diameter 30-60 × 10 -10 m) was determined by the alcohol method of desiccator. The measured data were accurate and reliable. However, when the specific surface area of ​​X-alumina (for desiccants, average pore diameter of 15-25x10-10 m) was measured by the drier alcohol method, the measured data was higher than the static BET method because: ①X-alumina pore radius is small, easy to make ethanol molecules capillary condensation;