Improvement of hydrogen sorption measurement using a Sieverts apparatus with consideration of thermal transpiration

Improvement of hydrogen sorption measurement using a Sieverts apparatus was performed by considering volumetric change due to the valve movement and the thermal transpiration. The newly suggested measurement method was evaluated by comparing the results from a blank test and a sample test with previous ones. The valve movement was found to be main measurement errors when the measurement temperature was near room temperature. The thermal transpiration became the major sources of errors as the difference between measurement temperature and room temperature increased. The modified equation for the PCI curve in this study gave the best performance compared with the previous ones at all measurement temperatures. These findings suggested the volumetric change due to thermal transpiration as well as the valve movement should be considered for more accurate measurements of hydrogen sorption. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.