Abstract
The Dubinin-Radushkevich potential theory was extended to include a term giving the effect of relative humidity on the uptake of adsorbate. This extended equation permits the adsorptive capacity of the activated charcoal in a respirator cartridge to be estimated for any combination of temperature, relative humidity, and concentration of contaminant. Application of this theory to previously published data of Werner showed a good correlation between theory and experiment. This equation is consistent with the experimental observations that 1) below a certain value, the relative humidity has little effect on the uptake of adsorbate, and 2) the effect of relative humidity, if observed, is more severe for lower than for higher concentrations of contaminant.