To validate the FT-CSFR method, the diffusion of 4% CO2 in 36.4% He, and 59.6% N2 on CALF-20 was measured. The gas mixture was achieved by diluting a gas stream from a manufacturer-certified gas cylinder of 9.91% CO2 balance He with N2 to achieve a 4% CO2 concentration. Also, data at 5 and 40% RH on CALF-20 and at 10, 26, and 40% RH on MOF-303 were collected to further validate the method since these conditions, along with the CO2/N2/He conditions, have all been reported in previous works. The rates obtained by FT-CSFR in this work are then compared to the rates obtained via CSFR in the previous studies. When applying the CSFR technique, the concentration swing is kept small to maintain a linear system response. Figure shows the swings in gas phase concentration and corresponding linearized swings in loading. With a small enough swing in the gas phase concentration, the isotherm can be approximated as locally linear.