Traceability of mass in air to mass in vacuum: results on the correlation between the change in mass and the surface chemical state

摘要

For the study of the practical means of a dissemination of the redefined kilogram, measurements on 1 kg mass artefacts were carried out, combining high precision mass determination and element-specific surface chemical analysis by x-ray photoelectron spectroscopy (XPS). In a sequence various processes were applied to steel, rhodium and gold artefacts. We studied the transfer from mass in air to mass in vacuum, several steps of hydrogen low-pressure plasma cleaning, cyclic exposure to air and vacuum and the natural contamination in air with time. Values for the gain and loss of mass due to the processes applied are provided. Reversible and irreversible sorption effects could be separated by means of mass determination, XPS and quartz crystal micro-balance. Possible pathways for the traceability of mass in vacuum to mass in air are discussed.