A Sieverts apparatus for small quantity samples has been implemented by employing a very small volume pressure reservoir and a sample chamber of less than 1 ml. The hydrogen storage capacity of a commercially available, HiPco (high pressure CO conversion) single-wall carbon nanotube (SWNT) was measured over a hydrogen pressure range of 0-35 Bar at room temperature. The sample contained approximately 5 wt% of residual Fe catalyst, and showed 0.17 wt% of hydrogen uptake capacity at 30 Bar of hydrogen pressure. Palladium nanoparticles were deposited on the SWNT via electrochemical method (EC) from H2PdCl4 solution. The storage capacity of the SWNT with EC-doped Pd was increased to 0.52 wt% at 30 Bar, which corresponds to the capacity enhancement by a factor between 2.8 and 3.1.