Realization and maintenance of the unit of capacitance with the PTB cross capacitor during the last ten years

A precise realization of the unit of capacitance is important for both the determination of the Josephson and the von Klitzing constants. The main design criteria of the PTB's cross capacitor, the maintenance of the unit of capacitance over the last ten years and a special capacitance measuring bridge for tracing back the electrode capacitance in the volt experiment to Si units are described in this paper.<
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