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Physical Measurement Laboratory

NIST Technical Note 1297

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1994 Edition (Supersedes 1993 Edition)

Web Version History

Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results

Barry N. Taylor and Chris E. Kuyatt

Brief summary

A method of evaluating and expressing uncertainty in measurement adapted from NIST Technical Note 1297.

 TN 1297 also available as a PDF file

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Contents

(Cover page)

Preface to the 1994 Edition
Foreword
1. Introduction
2. Classification of Components of Uncertainty
3. Type A Evaluation of Standard Uncertainty
4. Type B Evaluation of Standard Uncertainty
5. Combined Standard Uncertainty
6. Expanded Uncertainty
7. Reporting Uncertainty
8. References
Appendices
   A: Law of Propagation of Uncertainty
   B: Coverage Factors
   C: Statements of Uncertainty Associated with Measurement Results
D: Clarification and Additional Guidance
D.1 Terminology
D.2 Identification of uncertainty components
D.3 Equation (A-2)
D.4 Measurand defined by the measurement method; characterization of test methods; simple calibration
D.5 tp and the quantile t1-α
D.6 Uncertainty and units of the SI; proper use of the SI and quantity and unit symbols
D.7 References
Metrology and Physics

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Created July 6, 2009, Updated August 12, 2025
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