The electrochemical permeation and desorption techniques for studying the entry, transport and trapping of hydrogen in metals are outlined. These techniques are susceptible to numerous pitfalls. To obtain reliable data, the experimental conditions must be carefully controlled. As an example, the permeation of hydrogen through and the desorption of hydrogen from cathodically charged Arrnco iron membranes were investigated. The analysis of the partial permeation transients and then the analysis of the desorption rate of hydrogen from both sides of the membrane enabled determination the lattice diffusivity of hydrogen as well as the amounts and distribution of the diffusible and trapped hydrogen. (c) 2005 Published by Elsevier Ltd.