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NIST Technical Note 1297
1994 Edition (Supersedes 1993 Edition)

Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results

Barry N. Taylor and Chris E. Kuyatt

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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 To view documents which are "pdf files," Adobe Acrobat Reader is required. This software may be downloaded without charge.

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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  t_p and the quantile t_1-α

D.6  Uncertainty and units of the SI; proper use of the SI and quantity and unit symbols

D.7  References