We present results of investigations into improving methods by which gas sorption data are collected and reported. The focus is the accurate comparison of hydrogen storage capacities of different nanoporous materials. The aim is to produce a more rigorous approach to the assessment of the hydrogen storage capacities of different nanoporous materials through formulation of meticulous and systematic data collection routines for production of universally reproducible H-2 isotherms over a wide range of pressure and temperature conditions. Effects of a range of experimental variables are examined and recommendations for the optimisation of data collection routines are given. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.