A5079714418- Advanced Electrical Measurement Techniques
- Power Quality and Harmonics
- Magnetic Field Sensors Techniques
- Electrical and Bioimpedance Tomography
- Scientific Measurement and Uncertainty Evaluation
- Sensor Technology and Measurement Systems
- Advancements in PLL and VCO Technologies
- Magnetic Properties and Applications
- Analog and Mixed-Signal Circuit Design
- Power Transformer Diagnostics and Insulation
- Magneto-Optical Properties and Applications
- Non-Destructive Testing Techniques
- HVDC Systems and Fault Protection
- Seismic Waves and Analysis
- Vibration and Dynamic Analysis
- High-Voltage Power Transmission Systems
- Blind Source Separation Techniques
- Calibration and Measurement Techniques
- Lightning and Electromagnetic Phenomena
- High voltage insulation and dielectric phenomena
- Analytical Chemistry and Sensors
- Power Line Communications and Noise
- Advanced Sensor Technologies Research
- Radiative Heat Transfer Studies
- Risk and Safety Analysis
VSL Dutch Metrology Institute
2013-2024
University of South-Eastern Norway
2017
Nederlands Meetinstituut
2008
University of Manchester
2008
Radboud University Nijmegen
2008
We performed a metrological characterization of the quantum Hall resistance in 1 μm wide graphene bar. The longitudinal resistivity center ν=±2 plateaus vanishes within measurement noise 20 mΩ up to 2 μA. Our results show that quantization these is experimental uncertainty (15 ppm for 1.5 μA current) equal conventional semiconductors. principal limitation present experiments relatively high contact resistances regime, leading significantly increased across voltage contacts and heating sample...
A two-channel high-speed digitizer has been extensively characterized in the frequency range of 50 Hz-1 MHz. Measurements involved alternating-current (ac) flatness, phase, linearity, input impedance, and effects direct-current offsets, temperature, an internal self-calibration routine. digital antialiasing filter inside negatively affects ac flatness low-frequency region. An inverse compensation designed applied, which improves response with a factor 25-60 makes it flat within 25 μV/V up to...
A design of an automated cryogenic current comparator (CCC) resistance ratio bridge for routine measurements in a national metrology institute or standards laboratory is described. It employs type II CCC use low loss liquid helium storage vessel and can be continuously operated from the mains power via specialized isolated supplies. All parameters including servo control loops are digitally controlled. Noise sources system analysed using Allan deviation it demonstrated that non-white noise...
Over the last 15 years, research in ac Josephson voltage metrology has focused on two fundamentally different systems: programmable and pulse-driven standards (JVSs). This paper reports first high precision comparison between types of JVS. The METAS standard was moved from Switzerland to Netherlands be compared with Dutch system during four days November 2010. After a careful investigation systematic sources errors, made at frequency 500 Hz an rms amplitude 104 mV. At that level, difference...
We describe measurements with a pulse-driven Josephson arbitrary waveform synthesizer (JAWS) that uses ternary bit-stream generator as the bias source. This system is designed to be used an AC voltage standard. From these measurements, we conclude operational for root-mean-square voltages of up 220 mV. measured operating margins different synthesized numbers junctions, waveforms, and conditions. also present results on influence critical current margins.
We present measurements on a pulse-driven ac Josephson voltage standard (ACJVS) for frequencies up to 1 MHz. By automating our setup we were able perform systematic study of the frequency dependence ACJVS output. show that error caused by leads is major source when measuring at The squared error, which resonance in circuit, allows us make correction results an uncertainty µV V−1 level least 20 kHz.
A setup based on a direct current (dc) comparator, typically employed in high-current low-resistance calibrations, has been developed for the accurate calibration of dc ratios currents up to 600 A. For primary above 100 A, multiple turns conductor are made through device under test. full uncertainty analysis reveals that 1 part 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> total expanded (k = 2) zero-flux is limited by behavior...
A Josephson arbitrary waveform synthesizer (JAWS) has been developed in order to generate quantum-based ac voltage signals. The key component of this JAWS is a modified commercial 30-Gb/s pattern generator that can ternary patterns (containing the values 1, 0, and resulting bipolar pulses). new pulse-drive electronics have successfully tested by driving arrays with current pulses from 1 30 Gb/s study their current-voltage characteristics spectra
This paper describes the design and performance of a modular wideband high-voltage dc (HVDC) reference divider with ratio uncertainty less than 0.005% at 1000 kV. The has maximum nominal voltage kV when five 200-kV modules are stacked on top each other. is used for traceable calibration HVDC measuring systems in customers' laboratories. first priority was accuracy measurements. In addition, designed to have wide bandwidth, both enable measurement ripple voltages prevent damage during...
This paper describes the design and performance of a wideband high-voltage dc (HVDC) reference divider module. The module has nominal voltage 200 kV, it been designed so that number modules can be stacked to extend voltages up 1000 kV. module, or stack modules, will used for traceable calibration HVDC measuring systems in customers' laboratories. first priority was accuracy measurements. In addition, have wide bandwidth, both enable measurement ripple prevent damage during possible flashovers.
AC-DC measurements have been performed on a commercial thermal transfer standard (TTS) using pulse-driven ac Josephson voltage with small cryostat enabling shorter leads. A 20 mV RMS output was chosen, close to the maximum value that can be obtained without low-frequency compensation (at sigma-delta code amplitude of about 10 %) and upper limit TTS in its 22 range. The measured deviation at higher frequencies, which is due length leads, an order magnitude smaller than observed before normal...
The European Josephson arbitrary waveform synthesizer (JAWS) project addresses the lack of instrumentation and knowledge for accurate traceable measurement generation alternating (AC) voltage with waveforms. objective is to develop a standard based on JAWS, precise instrument that links generated effect, which in turn relates fundamental constants frequency. aims at synthesized voltages up 10 mV, frequencies kHz uncertainty smaller than 100 /spl mu/V/V as first step. This paper reports...
A pulse-driven AC Josephson voltage standard (ACJVS) generates calculable signals at low temperatures, whereas measurements are performed with a device under test (DUT) room temperature. The leads cause the output to show deviations that scale frequency squared. Error correction mechanisms investigated so far allow ACJVS be operational for frequencies up 100 kHz. In this paper, calculations presented deal these errors in terms of reflected waves. Impedance matching source side system, which...
The electrical characteristics of two different 1-V binary programmable Josephson arrays, an superconductor/insulator/normal conductor/insulator/superconductor-type array, and externally shunted superconductor/insulator/superconductor-type were investigated at ten metrology institutes. Various operational parameters evaluated compared using array voltage standard setups microwave frequencies around 70 GHz. results the measurements show that both arrays have been working very well main...
The European JAWS project addresses the lack of instrumentation and knowledge for accurate traceable measurement generation altemating (AC) voltage with arbitrary waveforms. objective is to develop a standard based on Josephson Arbitrary Waveform Synthesizer (JAWS), precise instrument that links generated effect, which in turn relates fundamental constants frequency. aims at synthesized voltages up 10 mV, frequencies kHz uncertainty smaller than 1 part 104. This paper reports progress...
A fully automated system has been developed for voltage calibrations where fast programmability and extremely low uncertainties are required. This is based on a binary Josephson junction array with smallest segment of one single junction. As an important application, the linearity 10 mV range digital nanovoltmeter was determined standard uncertainty better than 1 nV. further application system, ratios measured by -digit voltmeter in quantum Hall measurements to be × 10−9.
This paper describes a power measurement setup that is able to measure up the MHz region. The consists of commercial digitizer together with switch unit, and buffer amplifiers alternately voltage current channel. A reference AC voltmeter provides an absolute by simultaneous rms one channel, which significantly reduces need for flat frequency response setup. method described in this makes complex ratio measurements possible range 50 Hz 1 uncertainty few parts 10 <sup...
This paper describes design principles of a wideband HVDC reference divider. The modular divider will be used for traceable calibration measuring systems up to 1000 kV in customers' laboratories. first priority the was accuracy measurements. In addition designed have wide bandwidth, both enable measurement ripple voltages and prevent damage during possible flashovers.
The direct-current (dc) properties of a set recently developed wideband alternating-current (ac) shunts in the range 30 mA to 10 A are presented. characterization includes long-term drift, temperature coefficient, and power which all appear have effects on level 1-10 μΩ/Ω. After corrections for these effects, total uncertainty shunt resistance is between 1 3 These results prove suitability applications where both small ac-dc transfer differences (small phase angles) over whole frequency...
This paper describes the design and setup of different measuring systems for calibration commercial voltage current transformer test sets non-conventional instrument transformers. The are recently developed at national metrology institutes VSL, PTB, METAS TUBITAK within frame European project "FUTURE GRID - Non-conventional sensors future power grids". attained uncertainty is in order 10 ppm μrad testing analogue input 20 80 digital (IEC 61850-9-2) set.
A pulse-driven AC Josephson voltage standard generates calculable signals at low temperatures, whereas measurements are performed with a device under test room temperature. The leads cause the output to show deviations that scale frequency squared. So far, these where thought of as resonance, could be damped, filtered or corrected for. However, in this paper calculations and presented problem is caused by standing waves. Solutions for trying minimize compensate reflection
We describe the automation of a pulse-driven AC Josephson voltage standard (ACJVS) that uses ternary arbitrary bitstream generator as bias source. A heuristic method called downhill simplex is used to find best operating parameters optimized for largest margins. Measurements are presented showing difference between manual and automated tuning. From these measurements we conclude tuning algorithm ACJVS working properly.
A Josephson arbitrary waveform synthesizer (JAWS) has been used for the synthesis of bipolar voltage signals. The two major changes with respect to earlier work are use arrays consisting more junctions and a new type pattern generator. With multi-branch array from IPHT, synthesized sinusoidal voltages have amplitudes up 9.5 mV zero peak frequencies in range 100 Hz 150 kHz. For instance, sine wave 122 kHz, spectrum signal shows that higher harmonics at least 86 dB below fundamental....
A measurement setup is described, which has been developed at NMi Van Swinden Laboratorium for the automated of low-ohmic resistors. It based on a stand-alone commercial current range extender, enables measurements many resistors muOmega/Omega level. The software gives full insight in process