The process involves exposing a sample to nitrogen gas at different pressures and measuring the amount of gas adsorbed and desorbed. The data collected is used to generate an adsorption isotherm, which is a graph showing the relationship between the amount of gas adsorbed and the pressure. From the isotherm, various properties like surface area and pore size distribution can be determined using models such as the Brunauer-Emmett-Teller (BET) theory and the Barrett-Joyner-Halenda (BJH) method.
