Investigation of the long- and medium-term drift of Zener diode-based voltage standards

This work presents the results of a long-term study of the temporal behavior of Zener diode-based electronic voltage standards, which are commonly used to maintain a local representation of the SI volt. The long-term drifts of the 10-V outputs of commercially available standards are described by secular drift models whose parameters have been estimated by analysis of historical data obtained, over a ten-year period, from the results of bilateral comparison exercises. It is shown how data from within-group comparisons can be used to investigate medium-term deviations of a standard´s output from its uniform drift behavior. It is concluded that these medium-term deviations limit the predictability of a voltage standard´s output.