Quantum Electrical Standards at the BIPM

Quantum Electrical Standards at the BIPM

How the BIPM uses quantum electrical standards to support globally comparable electrical measurements.

 

Quantum electrical standards

How do we know that one volt is the same everywhere in the world?

Electrical measurements depend on standards that can be reproduced with exceptional precision. In modern electrical metrology, two quantum effects provide the basis for the most accurate electrical standards: the Josephson effect for voltage and the quantum Hall effect for resistance.

Since the revision of the International System of Units (SI), the numerical values of the elementary charge and the Planck constant have been fixed. This allows quantum electrical standards to provide practical realizations of SI electrical units.

The BIPM uses these standards as the basis for comparison and calibration services in voltage, resistance and capacitance, helping National Metrology Institutes (NMIs) maintain traceability to the SI and demonstrate the international equivalence of their electrical standards.

 

Why this matters

Electrical measurements underpin a vast range of applications, from electrical power grids and advanced manufacturing, through telecommunications and digital infrastructure, to electronics, manipulating a few electrons in novel devices.

 

From quantum standards to measurement services

Turning quantum effects into practical measurements

The BIPM helps turn quantum electrical standards into practical measurement services used by laboratories around the world.

 
 
Voltage

Josephson voltage standards

Josephson voltage standards use a quantum effect to produce highly stable voltage references. They allow the volt to be realized directly from fixed values of the elementary charge and the Planck constant.

The BIPM uses Josephson standards to support voltage calibration services and comparisons for NMIs, helping laboratories demonstrate the equivalence of their voltage standards and support their calibration and measurement capabilities.

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Resistance

Quantum Hall resistance standards

Quantum Hall resistance standards provide highly reproducible resistance references. They allow the ohm to be realized directly from fixed values of the elementary charge and the Planck constant.

The BIPM uses quantum Hall resistance standards as the basis for resistance calibration services and comparisons, including comparisons of NMIs’ primary quantum standards and their scaling to other resistance values.

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Linking quantum standards to other electrical quantities

Capacitance standards

Capacitance standards are linked to quantum Hall resistance standards through precision measurement techniques, enabling capacitance measurements to remain traceable to the SI.

The BIPM provides comparison and calibration services for capacitance standards, helping NMIs maintain internationally comparable electrical measurement capabilities.

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For measurement specialists

Explore the technical detail

This page provides a simple overview. Explore the resources below for technical details, services and related publications.

Electrical metrology

Technical information on BIPM electrical metrology services.

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Comparisons

Current and completed BIPM electrical comparisons.

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Calibrations

BIPM calibration services for electrical standards.

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Frequently asked questions

Find quick answers to common questions about quantum electrical standards and the BIPM’s work in electrical metrology.

What are quantum electrical standards?

Quantum electrical standards use quantum effects to provide highly reproducible electrical references. The Josephson effect provides the basis for voltage standards and the quantum Hall effect provides the basis for resistance standards.

How are quantum electrical standards linked to the SI?

Since the revision of the International System of Units (SI), the numerical values of the elementary charge and the Planck constant have been fixed. This allows quantum electrical standards to provide practical realizations of SI electrical units.

What is a Josephson voltage standard?

Josephson voltage standards use a quantum effect to produce highly stable voltage references. They allow the volt to be realized directly from fixed values of the elementary charge and the Planck constant.

What is a quantum Hall resistance standard?

Quantum Hall resistance standards provide highly reproducible resistance references. They allow the ohm to be realized directly from fixed values of the elementary charge and the Planck constant.

How is capacitance linked to quantum electrical standards?

Capacitance standards are linked to quantum Hall resistance standards through precision measurement techniques, enabling capacitance measurements to remain traceable to the SI.

How does the BIPM support electrical metrology?

The BIPM uses quantum electrical standards as the basis for comparison and calibration services in voltage, resistance and capacitance, helping National Metrology Institutes (NMIs) maintain traceability to the SI and demonstrate the international equivalence of their electrical standards.

Explore the BIPM Physical Metrology Department

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