Current comparator for both AC and DC ratio measurements with 10^- 8-level type-a uncertainty

Area of Science:

• Electrical Metrology
• Quantum Sensing
• Solid-State Physics

Background:

• Accurate alternating current (AC) and direct current (DC) ratio measurements are crucial for electric power metrology.
• Conventional current comparators utilize distinct technologies (electromagnetic induction for AC, SQUIDs for DC), creating a fragmented traceability system.
• A unified current standard is needed for emerging temperature power technologies.

Purpose of the Study:

• To present a compact, room-temperature AC/DC current comparator.
• To bridge the technological gap in AC and DC current metrology.
• To develop a unified current standard applicable to advanced power technologies and quantum electrical standards.

Main Methods:

• Integration of a diamond-based magnetometer utilizing nitrogen-vacancy (NV) centers.
• Development of a compact, cryogenics-free current comparator device.
• Characterization of the device's performance for both AC and DC signals.

Main Results:

• Achieved type-A uncertainty at the [Formula: see text] level.
• Expanded uncertainty reported at the [Formula: see text] to [Formula: see text] level for both AC and DC.
• Demonstrated system bandwidth up to [Formula: see text] without cryogenics.
• Performance comparable to conventional AC comparators.

Conclusions:

• A unified, cryogenics-free AC/DC current comparator has been successfully developed.
• The device offers enhanced precision, versatility, and applicability to DC resistance bridges in quantum electrical standards.
• This room-temperature platform facilitates further improvements in current metrology for advanced power applications.