1.1 This International Standard specifies a laboratory method for the measurement of hydrogen permeationand for the determination of hydrogen atom uptake and transport in metals, using an electrochemical technique.The term “metal” as used in this International Standard includes alloys. 1.2 This International Standard describes a method for evaluating hydrogen uptake in metals, based onmeasurement of steady-state hydrogen flux. It also describes a method for determining effective diffusivity ofhydrogen atoms in a metal and for distinguishing reversible and irreversible trapping. 1.3 This International Standard gives requirements for the preparation of specimens, control and monitoring ofthe environmental variables, test procedures and analysis of results. 01.4 This International Standard may be applied, in principle, to all metals for which hydrogen permeation ismeasurable and the method can be used to rank the relative aggressivity of different environments in terms ofthe hydrogen uptake of the exposed metal.