The mission of NIST is to promote U.S. innovation and industrial competitiveness by advancing measurement science, standards, and technology in ways that enhance economic security and improve our quality of life. To help meet the measurement and standards needs of U.S. industry and the nation, NIST provides calibrations, standard reference materials, standard reference data, test methods, proficiency evaluation materials1 , tools that facilitate the evaluation of measurement uncertainty , measurement quality assurance programs, and laboratory accreditation services that assist a customer in establishing traceability of measurement results.
Metrological traceability  requires the establishment of an unbroken chain of calibrations to specified reference standards: typically national or international standards, in particular realizations of the measurement units of the International System of Units (SI). NIST assures the traceability to the SI, or to other specified standards, of measurement results that NIST itself provides, either directly or through an official NIST program or collaboration. Other organizations are responsible for establishing the traceability of their own results to those of NIST or other specified references. NIST has adopted this policy statement to document the NIST role with respect to traceability.
To support the conduct of its mission and to ensure that the use of its name, products, and services is consistent with its authority and responsibility, NIST:
In text references:
 Homogeneous materials or artifacts that are used to test and evaluate the measurement performance and fitness for purpose of measuring systems (VIM §3.2) or measurement procedures (VIM §2.6).
 NIST Uncertainty Machine and NIST Consensus Builder, with user’s manuals available online, and supported by peer-reviewed publications: Lafarge & Possolo (NCSLI Measure Journal of Measurement Science 10(3): 20-27); Koepke et al. (2017, Metrologia 54(3): S34-S62, DOI 10.1088/1681-7575/aa6c0e).
 The abbreviated term “traceability” is sometimes used to mean “metrological traceability” as well as other concepts, such as “sample traceability” or “document traceability” or “instrument traceability” or “material traceability”, where the history (“trace”) of an item is meant. Therefore, the full term of “metrological traceability” is preferred if there is any risk of confusion (VIM §2.41, Note 8).
 Joint Committee for Guides in Metrology (2012, 3rd Edition, International Bureau of Weights and Measures (BIPM)). The VIM is freely available online at https://jcgm.bipm.org/vim/en/.
1Terms are defined in Metrological Traceability: Frequently Asked Questions and NIST Policy