A mathematical model for Rn sampling by activated C adsorption

This paper describes a diffusion/adsorption model that has been developed for the transport of Rn in an activated carbon porous bed. It is useful in studying the carbon canister Rn sampling technique used for monitoring Rn levels in air. The model calculates the amount of Rn adsorbed by the canister for various situations. The predictions of the response of the canister to both constant, as well as a periodic varying concentration of Rn in the surroundings, compares very well with experimental data. Based on this model, it is possible to simulate on a computer the response of the canister for an arbitrarily varying surrounding Rn level. Such computer simulations are effective tools in the design of a more accurate carbon canister monitor.