Vacuum vs Argon Technology for Hydrogen Measurement

Within the framework of this paper, we review the development of the problem of hydrogen diagnostic for metals. Metal sample enrichment techniques based on hydrogen vacuum extraction method used for a long time. Development of the industrial control technologies has led to the almost complete replacement of vacuum techniques with “atmospheric” ones. As a result systematic errors have occurred. These errors lead to multiple differences between certified and measured hydrogen concentration values for standard samples.
In this paper, we analyze reasons of systematic errors genesis observed for hydrogen measurements while applying the thermal conductivity cell technique. As a result, we demonstrated that measurements resulting from samples heating and melting in the inert gas flow depend on its heat capacity and surface temperature of the melting pot. Due to this reason, one can obtain multiple errors and even negative values for measurements of a low hydrogen concentration."