An electrochemical permeation method was used to measure the diffusivity of H in 3N5-purity material at temperatures of between 10 and 80C. It was found that the data for 0.5M H2SO4 electrolyte solution represented the highest diffusivity.

C.W.Su, J.K.Wu: Journal of Materials Science Letters, 1988, 7[8], 849-50