The specific surface area of active carbon is one of the important physical structure parameters, and the accuracy of its measured value is essential for realistic reference significance. The volumetric method was adopted to measure the specific surface area of active carbon by NOVA2000e surface area & pore size analyzer, and the factors affecting the measured value of specific surface area of active carbon, such as the conditions of sample pretreatment and adsorption point numbers, were discussed. The results show that the optimum condition of sample pretreatment is to desorbe for more than 5 h at 300℃. The measured value of specific surface area of sample treated under such conditions is closer to the actual value. The measured value of specific surface area of sample by multipoint BET method attains better accuracy with the increase of adsorption points. When the adsorption point is 5, the relative error of the measured value is only 1.15%. Single point BET method can be used as an approximate method, and the relative error of the single point BET value measured by this analyzer is about 5%. In the allowable experimental accuracy range, the measurement of materials surface area by the single point BET method is quite simple and effective.%活性炭的比表面积是其重要的物理结构参量之一,其实测值的准确性具有实际参考意义.文中应用NOVA2000e型比表面积和孔隙度分析仪,采用容量法测定活性炭的比表面积,研究样品预处理条件及吸附点数量等因素对测量结果的影响.结果表明:样品的最佳预处理条件为脱气温度300℃,脱气时间不少于5h.在此条件下处理的样品比表面积测定值更加接近真值.随着所选取的吸附点数量的增加,多点BET法比表面积测定值更加准确,当选取的吸附点的数量为5点时,相对误差仅为1.15％.单点BET法可作为一种近似测定方法,其实验仪器单点BET测量值的相对误差约为5％.在实验精确度允许的范围内,单点BET法测定材料的比表面积具有简捷、快速的优点.
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