The project

Objectives

The overall objective of the project is to implement quantum techniques for measurement of AC voltage in the increased bandwidth up to 100 kHz and amplitude to 10 V, and to transfer knowledge by sharing information and using open-source software.

The specific objectives of the project are:

To develop methods, techniques, algorithms, and control software for calibration of AC voltage sources and measurement instruments at frequencies up to 100 kHz and 7 V RMS amplitude with an uncertainty better than 10 μV/V by utilising sub-sampling and differential sampling and by expanding on the methods, algorithms, and software developed in previous EMRP and EMPIR projects (WP1).
To develop three working implementations of the expanded open quantum sampling standard working up to the increased bandwidth and specified voltages based on existing commercial devices (WP2).
To transfer the expertise in AC Josephson standards to emerging NMIs through the exchange of knowledge and know-how, and to develop a coordinated approach for the replacement of AC traceability from thermal transfer techniques to Josephson standards in the increased bandwidth (WP3).
To facilitate the take-up and long-term operation of the methods, techniques, know-how, and measurement infrastructure for AC measurements developed in the project by the measurement supply chain (NMIs and DIs, calibration and testing laboratories, EMN-Q and EMN SEG), and end users(industry, instrument manufacturers) (WP4).

WP1: Techniques, algorithms and software for calibration using the sub-sampling method

This work package aims to provide guidance for the successful construction of AC quantum voltmeters that allow differential sampling up to the kHz range and sub-sampling up to 100 kHz with a target uncertainty better than 10 μV/V. In a pioneering move, the project not only considers simple sine waves but also multi-tone waveforms.

WP2: Development of working implementations of new quantum sub-sampling standards

The aim of this work package is to further exploit knowledge on the use of programmable Josephson voltage standards (PJVS) by developing novel working implementations of Wideband Quantum Voltage (WBQV) standards based on sub-sampling methods. The development will focus on permanent integration and an optimised combination of PJVS with high-precision and high-bandwidth waveform digitizers. This will provide a robust reference metrological framework, laying the foundation for the step change from thermal converter techniques to quantum standards, as expected in the ongoing implementation stage of the new quantum SI. The quantum sub-sampling method provides substantial advantages for enhancing the traceability of LF-AC quantities, such as voltage, current, power, and energy, compared to the conventional and time-consuming AC-DC transfer method. Additionally, the method will be adapted to provide traceability for waveforms with harmonic content and non-RMS quantities and has great application potential in the domain of synchronised voltage measurements.

WP3: Transfer of expertise within the consortium and a coordinated approach to establish traceability to quantum standards

The aim of this work package is to ensure the transfer of knowledge and expertise between participants within the consortium, the development of coordinated approach to establish traceability to quantum standards, preparation for future comparisons of AC voltage and the development of working procedures by those participants that have developed WBQV standards.

WP4: Creating impact

The aim of this work package is to disseminate and communicate the project’s outcomes, taking into consideration stakeholders’ input, and to encourage exploitation and uptake of the projects results and outputs. In this way, the community of stakeholders (calibration and test service providers, NMIs, measuring instrument makers, standardisation bodies, industry, etc.) will be able to make the most of the project. The documentation produced in the project for the WBQV standard will cover measurement methods, hardware, algorithms, calculations, software, uncertainty estimation, and ways to convert existing PJVS standards to wideband quantum systems. The documentation will serve as a primary means to spread the results of the project to any interested users. The consortium will engage with stakeholders and end-users to promote quantum systems as a way to achieve more precise wideband voltage measurement.

WP5: Management and coordination

This work package deals with the organisation and coordination of the project.

News and events

Month 6 online meeting – 11 December 2024

On December 11, 2024, the M6 online meeting took place. Key highlights included updates from Work Package 1 (WP1), where PTB shared measurement results indicating minimal card-to-card differences in NI 5922 digitizers and demonstrated the Fluke 8588 transfer function. CMI introduced their software for automating digitizer filter measurements, and Supracon offered their system for testing. The next meeting is scheduled for March 2025.

YouTube channel, private repository and software repository – 2 August 2024

We are glad to present our YouTube channel: www.youtube.com/@WAC-Euramet

And our first video by Martin Šíra from Czech Metrology Institute (CMI) presenting the project: https://www.youtube.com/watch?v=52hMT8jid_o

Please like, subscribe and share!

Additionally, a private repository and a software repository have been created. Check the related sections for addresses.

Project initiation and kick-off meeting – 4 June 2024

From June 4th to 6th, 2024, the picturesque city of Braunschweig, Germany, played host to the much-anticipated initiation and kick-off meeting of our new Project WAC. This three-day event marked the formal launch of a collaborative effort poised to drive innovation and achieve remarkable milestones in AC metrology.

A summary of WAC has been released for publicly. Please find it in the following link

Consortium

The consortium consists of 8 National Metrology Institutes (NMI) and Designated Institutes (DI): CEM, CMI, FER, INRIM, INTI, JV, PTB and TUBITAK, two universities: SUT and UNICA, and two companies: LeftRight and Supracon.

CMI (Czech Republic) has a wide experience in the measurement of electrical quantities and currently has the third-widest coverage of electrical quantities in Europe.
CEM (Spain) has operated quantum electrical standards for several years as Josephson Voltage and Quantum Hall effect standards.
FER (Croatia) has experience with DC Josephson Array Voltage Standards, digitizers, sampling techniques, and other types of DC and AC measurements, specifically at lower frequencies (amplitude and phase).
INRIM (Italy) has extensive experience in LF-AC primary metrology, in the development of traceable calibration methods for power and power quality standards based on sampling techniques, and in open-source software for static and dynamic sampling power and PQ measurements.
JV (Norway) has ongoing experience in AC/DC transfer, quantum Hall resistance, and sampling of electrical power.
PTB (Germany) has contributed significantly to the development and present status of DC and AC Josephson voltage standards. PTB has pioneered a number of applications as the “AC quantum voltmeter” for measuring AC voltages up to 100 kHz.
TUBITAK (Türkiye) has extensive experience in DC and quantum metrology and LF-AC primary metrology. TÜBİTAK developed traceable calibration methods for voltage metrology based on sampling techniques.
INTI (Argentina) has experience in DC and LF-AC metrology. It has DC and AC Josephson voltage standards and is highly experienced in sampling electrical quantities.
LeftRight (Slovenia) has extensive experience in AC metrology at the highest accuracy level and specifically in state-of-the-art sampling and signal processing techniques.
Supracon (Germany) is an established industrial market player in the field of Josephson Voltage Standard systems. Supracon’s superconducting chip fabrication technology is the base of its system instrumentation business.
SUT (Poland) is one of the largest and top-ranked technical universities and an important hub of industrial research.
UNICA (Italy) has a long-standing experience in the design, implementation, and characterisation of measuring systems as Smart Grids, synchronisation in distributed measurement systems, and power quality monitoring.