Measurements have been performed of the hydrogen contents in reference samples of aluminum alloy using the methods of vacuum hot extraction, vacuum melting and melting into the graphite crucible in the flux of gas carrier or argon carrier fusion method. The effect of additional "squeezing out" of hydrogen from the metal under its crystallization was not observed. It has been shown that during the sample heating time typical for the analysis by argon carrier fusion method the bound hydrogen with high activation energy is not extracted completely. This leads to errors in performed measurements. It has been proved that the mean velocity of hydrogen transport and mean coefficients of diffusion depend on the initial population of the energy levels, and they can vary for the same material. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.