Porous adsorbents are widely used in separation and purification, gas storage, and industrial catalysis, and the determination of adsorption isotherms is of great significance for studying adsorption properties. Aiming at solving the difficulty that the traditional volumetric method is easily affected by the temperature distribution along the pipeline, the paper introduces an adsorption measurement method based on flow calibration. The error transfer of both methods is analyzed, and the influence of the structure parameters, physical parameters and instrument accuracy on the adsorption measurement is compared. The results show that increasing the calibration ball volume and sample chamber volume can improve the adsorption measurement accuracy of the traditional volumetric method, and increasing the sample volume, excess adsorption amount, skeleton density and instrument accuracy can improve the measurement accuracy of both methods. Compared to the traditional volumetric method, the method based on flow calibration has fewer error factors and can achieve lower measurement errors. The results can help improve the measurement accuracy of the volumetric method.

Keywords： adsorption ; measurement ; equation of state ; error analysis ; mass flow controller ; uncertainty