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A sampling current ratio measurement system has been developed, tested, and validated for the accurate complex ratio measurement of ac current transducers. Calibrations can be performed for primary currents up to 10 kA with typical expanded uncertainties of 5\cdot 10^\mathrm \mathbf -6 in magnitude and 5 $\mu $ rad in phase ( $k=2$ ). A unique property of the system is the use of digitizers for sampling of the secondary current signals and step-down transformers with a large number of current ratios. Therefore, the system does not require the current transducer under test to be a current transformer having a nominal ratio equal to the reference current transformer. Furthermore, it allows for the accurate calibration of a large variety of different current transformers and other types of current transducers. A bilateral comparison between VSL and NRC confirms the stated uncertainty. [ABSTRACT FROM PUBLISHER]

The European Josephson arbitrary waveform synthesizer (JAWS) project addresses the Jack of instrumentation and knowledge for accurate and traceable measurement and generation of alternating (AC) voltage with arbitrary waveforms. The objective is to develop a standard based on a JAWS, a precise instrument that links the generated voltage to the Josephson effect, which in turn: relates voltage to fundamental constants and frequency. The standard alms at synthesized voltages up to 10 mV, frequencies up to 10 kHz and uncertainty smaller than 100 μV/V as a first step. This paper reports on the progress in developing the key components for JAWS. [ABSTRACT FROM AUTHOR]

A high accuracy current source has been developed for the generation of very small currents (below 200 pA) based on applying a linear voltage ramp to a capacitor. Using software-controlled compensation for the nonlinearity of the voltage ramp, a stable current can be reached within a few seconds. A voltage ramp within typically 10.10-6 of any desired value between less than 1 mV/s and several hundreds of mV/s can be realized. Using a high quality air-dielectric capacitor, currents below 200 pA can be generated With an uncertainty of 20 μA/A (k = 2), with a lower limit 0f 2.0 aA (k=2). [ABSTRACT FROM AUTHOR]

Presents a study that exploited two complementary single electron tunneling devices for use in electrical current metrology. Set current source; Current steps for the R-pump with smaller junctions for different frequencies and series resistances; Summary and conclusion.

Presents a study that analyzed different measurements setups for a programmable Josephson voltage standard. Arrays and measurement setups; Results of the study; Conclusion.