This work explores MEMS (Micro-ElectroMechanical Systems) potentialities to produce flexible AC voltage references through mechanical-electrical transduction that could be used for high precision electrical metrology and for applications in miniaturized instrumentation. AC voltage references ranging from 2 V to 90 V have been designed and fabricated using the same Epitaxial Silicon On Insulator (SOI) Surface Micromachining process that permits an accurate control of both dimensions and material properties. The measured MEMS AC voltage reference values have been found in a good agreement with the calculations performed with Coventor software. These test structures have been used to develop the read-out electronics to drive the MEMS and to design a second set of devices with improved characteristics. Deep Level Transient Spectroscopy measurements carried out on the new MEMS showed resonance frequencies of about a few kilohertz, which makes it possible to have AC voltage references working from about tens of kHz. Moreover, the stability of the MEMS out-put voltage at 100 kHz has been found very promising for the best samples where the relative deviation from the mean value over almost 12 h showed a standard deviation of 6.3 × 10^-6, which is a very good result.

We present our experimental set-up and discuss the results obtained within the framework of the ANR-TRIMET project which aim was the closure of the quantum metrological triangle (QMT) at a relative uncertainty level of 1 part in 10⁶. This experiment consists in achieving Ohm’s law with the three effects used and investigated in quantum electrical metrology: Josephson effect (JE), quantum Hall effect (QHE) and single electron tunnelling effect (SET). The aim is to check the consistency of the phenomenological constants K_J, R_K and Q_X associated with these effects and theoretically expressed with the fundamental constants e and h (elementary charge and Planck constant, respectively). Such an experiment is a contribution for a new definition of the International System of Units (SI). Also, the obtained results are a first step towards a determination of e.

To fill the gap of intermediate frequencies 100 kHz–100 MHz for which still remains a lack of traceability of impedance measurements for recent measurement instruments, LNE has established the traceability of a 4 ports vector network analyzer (VNA) and applied the method of Suzuki to measure four terminal pair impedances (Z4TP). In order to establish the traceability of the 4 ports VNA, used to measure Z4TP, LNE has investigated successively two different ways. We have developed 4TP calculable thin-film resistors, and then we have established the traceability of the “Unknown Thru” calibration method. We will show the two approaches and the measurement results up to 10 MHz obtained for a 1 000 pF capacitor with the associated uncertainties.

This paper describes the development of a new power standard based on a commercial thermocouple sensor. A calibration with a twin microcalorimeter has been performed in order to determine the effective efficiency of the sensor. A calibration using thermal transfer allows us to validate the results got with the microcalorimeter. LNE has got a new power standard for low frequencies.

Two compensated current comparators with magnetic flux cancelling have been made in the 1970s by the LCIE (Laboratoire Central des Industries Electriques) as a reference for high current transformers calibration for currents up to 50 kA at industrial frequencies 50 Hz, 60 Hz and 400 Hz. They are associated with manually operated electronic equipments: an adjustable phantom burden and a ratio error set capable to provide with high accuracy the quadrature and the in-phase components of the current transformer errors. This article presents the work that has been done to entirely redefine theses devices by abandoning the idea of a direct servo system of the old equipment and replacing it by a software servo that offers high calibration stability, better incertainties and fully controllable by a remote computer via an USB connection, allowing full automation of the procedure.

This paper presents our work for the measurement of the complex permittivity of liquids, carried out in the framework of a European Metrology research project entitled “Traceable measurement of field strength and SAR for the Physical Agents Directive”. One of he aims of this project was to establish the traceability of the specific absorption rate measurements to the SI up to 10 GHz. We use a vector network analyser to measure the S21 parameter of coaxial cells containing the liquid under test (a reference liquid or an equivalent tissue liquid). The method does not require the network analyser to be calibrated in terms of impedance. In fact, only the length of the coaxial cell and the working frequency need to be known.

This paper presents the development of a new 2.4 mm coaxial twin load microcalorimeter and the development of the thermoelectric power sensors used as radiofrequency power standards. The effective efficiency is measured and results are presented for two types of sensors.

A method for determining the electromagnetic properties of Lead Zirconate Titanate (PZT) thin films is presented in this paper. At first we introduce a broadband characterization method based on the extraction of the intrinsic properties of substrate supporting a coplanar waveguide and then we perform an accurate on-wafer TRL calibration technique to measure the permittivity of the PZT thin film embedded in a coplanar waveguide.

This paper describes the development of a power standard based on thermocouple sensors. This work has been done in the framework of the fabrication of a microcalorimeter to destination of a foreign National Metrology Institute. The calibration has been performed in order to determine both the effective efficiency and the uncertainty for 21 frequency points up to 50 GHz. LNE expands its capability for manufacturing broadband (DC-50 GHz) primary calibration systems for RF power.

A system to mesure 8/20 μs (front time/time to half value) impulse currents from 5 kA to 50 kA (peak value) has been developed at LNE. The system relies on the use of non-invasif wideband (maximum 4 MHz) current sensors, of a 12 bits digitiser with a maximum sample rate of 100 Mega-samples per second and of a data acquisition and treatement software. The values of the expanded uncertainties (k = 2) are 1.4 mA·A⁻¹ for the peak value and 15 ns·μs⁻¹ for impulse current time parameters.