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OWM Frequently Asked Questions (FAQs)
The following are a series of specific topic FAQs related to weights and measures, legal metrology, and the metric (SI) program. If you don't find the answer to your question on the pages below, feel free to contact us at owm [at] nist.gov (owm[at]nist[dot]gov).
Specific Topic FAQs:
Most Frequently Asked Questions:
Please contact your State's weights and measures authority. NIST OWM provides a list of State weights and measures programs with contact information here.
If you have a complaint and/or inquiry, you may contact your State Weights and Measures authority for assistance. Please see the list of State Directors for contact information.
All countries have recognized and adopted the SI, including the United States. There are still countries that are amending their national laws to adopt a mandatory metric policy and others pursuing voluntary metrication. From a technical perspective, it’s impossible to avoid using the metric system as all measurement units (including non-SI or U.S. customary units) are defined in terms of the SI. The NIST blog article, Busting Myths about the Metric System, discusses some common misconceptions about the status of U.S. metrication. Learn more about U.S. Metrication and explore these Metrication FAQs for additional information.
The Metric (SI) Program page contains current SI information and additional resources including further information related to U.S. Metrication.
As of August 16, 2023 the physics.nist.gov historic SI Units site has permanently retired. Please contact TheSI [at] nist.gov (TheSI[at]nist[dot]gov) with comments, questions or concerns.
OWM provides a series of metrology training courses and webinars for the state metrology laboratories, metric and STEM educators, and the weights and measures community. Please see the OWM Training and Events calendar.
Our customers can request specific OWM training or OWM products through the OWM Contacts System which serves as an online storefront. Please see the Help for more information.
These are uniform (i.e., representing all stakeholders) documentary standards that are critical to consumer protection, economic growth and trade. They help ensure that consumers get what they pay for and that sellers get fair payment for the goods and services they provide.
These published standards provide technical rigor (e.g., technical specifications, test procedures and labeling requirements) when weighing and measuring products and services for sale, such as a pound of beef, a gallon of gasoline, or a mile driven in a taxicab.
As a non-regulatory Federal agency, NIST does not regulate the use of weights and measures. Weights and measures are regulated by the States. However, through the NIST Organic Act, Congress authorized NIST to cooperate with the States in securing uniformity in weights and measures laws and methods of inspection.
It is estimated that weights and measures regulations impact commercial transactions involving approximately 45 % of the 2022 U.S. Gross Domestic Product (GDP). This included a range of products and services sold on the basis of weight or measure or subject to price verification inspections in the U.S.
For a complete list of products and services and their estimated values for sales, please see here.
Legal Metrology refers to the system of laws that regulate measuring instruments subject to legal control, such as those used in trade and commerce (grocery store scales and gasoline pumps) and law enforcement (speed meters and breath analyzers).
Weights and Measures generally specifies the usage and performance of measuring devices used to test regulated measuring instruments.
Learn more about this topic here...
NIST doesn’t set standards itself. The documentary standards that NIST publishes are developed via a consensus process that involve all stakeholders. The U.S. standards development system is voluntary, decentralized, consensus-based, and driven by public sector needs. NIST does not decide to which standards are developed and/or published.
NIST brings together stakeholders, provides technical guidance, and facilitates the process to develop the standards. NIST is responsible for the overall content, interpretation, and maintenance of these standards as published through NIST and the Department of Commerce.
For further information, please contact owm [at] nist.gov (owm[at]nist[dot]gov)