Surface Area is helpful to determine how materials react to other materials, or how they dissolve or burn. In order to determine surface area a sample contained in a tube is pretreated by evacuation, including heat, vacuum and some flowing gas to remove contaminants from the surface. The material is then cooled to cryogenic temperatures. An adsorptive is added to the material at controlled pressure increments. After each dose of adsorptive, the pressure is equilibrated and the quantity adsorbed is calculated. After the area is covered by adsorbed gas molecules, the surface area can be calculated.