The Devanathan-Stachurski-cell is the most commonly used electrochemical technique for the investigation of the hydrogen trapping properties of a material. In this set-up, a flux of hydrogen atoms diffuses through a metal membrane under study. The atoms are subjected to the heterogeneities naturally present in the lattice of the metal, acting as traps. This matter influences the diffusion of hydrogen, which is strongly microstructure related. In this paper, we apply a numerical model to different iron-alloys to determine the hydrogen trapping parameters characterizing the materials. We highlight the complexity of the hydrogen trapping mechanism which needs to be further investigated.