PhD abstract

The comparison of electrical quantities expressed in units of the International System of Units (SI) and the same quantities generated from quantum effects is a direct way of determining physical constants. The determination of the von Klitzing constant (quantum of resistance) from a calculable capacitor is a part of this process. The last determination of this constant was conducted at LNE in 2000 with an uncertainty of 5×10-8. To achieve a target uncertainty of 1×10-8, the LNE decided to build a new standard capacitor and improve the associated measurement chain. The work presented here is implemented in the framework of the design/amelioration and the characterization of the measurement chain leading to the relative uncertainty of 1×10-8. Exploratory studies were also conducted about the possible partial or full automation of elements of the measurement chain.

Key words

coaxial AC bridges for impedance comparison, standard transformers, metrology, electricity, instrumentation