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Office of Weights and Measures

The Office promotes uniformity, equity, and SI use and traceability in weights and measures by advancing national and international legal metrology standards, test procedures, capabilities, and training.

The NIST Office of Weights and Measures (OWM) works to ensure that consumers get what they pay for, and sellers get fair payment for the goods and services they sell, by promoting a uniform and technically sound system of weights and measures. This, in turn, promotes consumer confidence and helps ensure fair competition for U.S. commerce that spans from local business operations to a global scale.

Our OWM Staff  work with a range of industry sectors -- such as the retail sales, petroleum and chemical products, and transportation, including emerging commercial market sectors such as charging of electric vehicles and e-commerce. We also work closely with our Customers and Stakeholders, including international and national standards development organizations, Federal agencies, State laboratory and regulatory officials, and metric program educators. OWM’s Products and Services include technical guidance related to weights and measures applications, legal metrology documentary standards, promotion of the metric system, SI use and traceability, and training for industry, State laboratory metrologists, and weights and measures officials.

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Originally established in 1836 as the “Office of Construction of Standard Weights and Measures”, OWM also remains the oldest office at NIST. For more information, see A Brief History of OWM.

News and Updates

SI Prefix Progress

In December 2022, the BIPM SI Brochure (9th Edition, December 2022, V2.01) was published to include the four new International System of Units (SI) prefixes

Projects and Programs


5841 Mass Metrology Seminar

Mon, Apr 10 - Fri, Apr 21 2023
The Mass Metrology Seminar is a two-week, "hands-on" seminar. It incorporates approximately 30 percent lectures and 70



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