Improvements of the Measurement Chain for the Determination of the von Klitzing Constant $R_{K}$

This paper presents the improvements of the impedance measurement chain that is used for the determination of the von Klitzing constant R
_K
at the Laboratoire National de metrologie et d'Essais. The design principles of the new Thompson-Lampard calculable cross capacitor are briefly given. The calculable coaxial resistors and resistance transfer standards with frequency variation of less than 1 times 10-7/kHz from dc to 1592 Hz have been fabricated and characterized.