Gas adsorption is the process of gasses coming into contact with a solid, and part of the gas being taken up by the solid, i.e. being adsorbed (note, different to absorb).
The GDS Adsorption cell is a Twin Cell based system used for the Adsorption of a Gas onto a chosen sample. One chamber will have a gas with a known volume and pressure. The second chamber will hold a sample with known volume under a vacuum. The gas is then introduced to the sample chamber and the process of adsorption begins.