Physical Metrology Department
From mass standards and quantum electrical measurements to the calibrations and comparisons used by laboratories worldwide, the BIPM Physical Metrology Department helps ensure that measurements remain traceable to the International System of Units (SI) and internationally comparable.
Turning measurement science into trusted results
The BIPM Physical Metrology Department develops and maintains reference measurement capabilities in mass and electrical metrology. Working with National Metrology Institutes (NMIs), it supports the realization and dissemination of the SI through reference standards, calibrations, international comparisons and scientific coordination.
This work enables national standards to be connected to internationally agreed references and supports confidence in measurements used in science, industry, trade and emerging technologies.
Where our work matters
Reliable physical measurements underpin many areas of day-to-day work and life. Below are a few examples.
Science
High-accuracy measurements for scientific research and experiments.
Industry
Traceable measurements used in manufacturing and industrial applications.
Trade
Comparable measurements that provide confidence across markets and borders.
Emerging technologies
Measurement references for developing and high-precision technologies.
Explore the Department’s work
Explore the Department’s work on the kilogram, quantum electrical standards and calibration and comparison services.
Building physical metrology expertise
The BIPM builds physical metrology expertise through comparisons for Member States, alongside knowledge-transfer initiatives and expert learning resources.
Comparison activities
Opportunities for scientists to exchange expertise while comparing measurement standards.
Video explainers
Expert presentations, technical meetings and learning resources for the physical metrology community.
Frequently asked questions
Find quick answers to common questions about physical metrology, the SI, calibrations and comparisons.
What does the BIPM Physical Metrology Department do?
The BIPM Physical Metrology Department develops and maintains reference measurement capabilities in mass and electrical metrology. Working with National Metrology Institutes, it supports the realization and dissemination of the SI through reference standards, calibrations, international comparisons and scientific coordination.
Why are international comparisons needed?
International comparisons allow laboratories to demonstrate the equivalence of their measurement standards and support the international recognition of their calibration capabilities.
Where can I find calibration and comparison information?
Technical information is available through the BIPM mass metrology page and electrical metrology page, while comparison results and internationally recognized capabilities are published through the BIPM Key Comparison Database (KCDB).
International scientific coordination
Related Consultative Committees
The CIPM Consultative Committees bring together international experts to coordinate and advise on specific areas of metrology.
Explore the BIPM’s other Departments
Discover how the BIPM’s scientific and operational Departments work together to support the worldwide measurement system.
Explore all BIPM Departments →