PD 6461-3:1995

Committees responsible
national foreword
Foreword
0 Introduction
1 Scope
2 Definitions
   2.1 General metrological terms
   2.2 The term "uncertainty"
   2.3 Terms specific to this Guide
3 Basic concepts
   3.1 Measurement
   3.2 Errors, effects, and corrections
   3.3 Uncertainty
   3.4 Practical considerations
4 Evaluating standard uncertainty
   4.1 Modelling the measurement
   4.2 Type A evaluation of standard uncertainty
   4.3 Type B evaluation of standard uncertainty
   4.4 Graphical illustration of evaluating standard
        uncertainty
5 Determining combined standard uncertainty
   5.1 Uncorrelated input quantities
   5.2 Correlated input quantities
6 Determining expanded uncertainty
   6.1 Introduction
   6.2 Expanded uncertainty
   6.3 Choosing a coverage factor
7 Reporting uncertainty
   7.1 General guidance
   7.2 Specific guidance
8 Summary of procedure for evaluating and expressing
   uncertainty
Annex A - Recommendations of Working Group and CIPM
      A.1 - Recommendation INC-1 (1980)
      A.2 - Recommendation 1 (CI-1981)
      A.3 - Recommendation 1 (CI-1986)
Annex B - General metrological terms
      B.1 - Source of definitions
      B.2 - Definitions
Annex C - Basic statistical terms and concepts
      C.1 - Source of definitions
      C.2 - Definitions
      C.3 - Elaboration of terms and concepts
Annex D - "True" value, error, and uncertainty
      D.1 - The measurand
      D.2 - The realized quantity
      D.3 - The "true" value and the corrected value
      D.4 - Error
      D.5 - Uncertainty
      D.6 - Graphical representation
Annex E - Motivation and basis for Recommendation INC-1 (1980)
      E.1 - "Safe", "random" and "systematic"
      E.2 - Justification for realistic uncertainty evaluations
      E.3 - Justification for treating all uncertainty
            components identically
      E.4 - Standard deviations as measures of uncertainty
Annex F - Practical guidance on evaluating uncertainty
          components
      F.1 - Components evaluated from repeated observations:
            Type A evaluation of standard uncertainty
      F.2 - Components evaluated by other means: Type B
            evaluation of standard uncertainty
Annex G - Degrees of freedom and levels of confidence
      G.1 - Introduction
      G.2 - Central Limit Theorem
      G.3 - The t-distribution and degrees of freedom
      G.4 - Effective degrees of freedom
      G.5 - Other considerations
      G.6 - Summary and conclusions
Annex H - Examples
      H.1 - End-gauge calibration
      H.2 - Simultaneous resistance and reactance measurement
      H.3 - Calibration of a thermometer
      H.4 - Measurement of activity
      H.5 - Analysis of variance
      H.6 - Measurements on a reference scale: hardness
Annex J - Glossary of principal symbols
Annex K - Bibliography
Alphabetical index
Figures
Tables

Establishes general rules for evaluating and expressing uncertainty in measurement that can be followed at various levels of accuracy and in many fields. Primarily concerned with the expression of uncertainty in the measurement of a well defined physical quantity, the measurand, that can be characterised by an essentially unique value. Gives general rules for evaluating and expressing uncertainty in measurement rather than detailed, technology specific instructions. Coverage includes: definitions, basic concepts, and determining expanded uncertainty. IDENTICAL to ISO Guide to the expression of uncertainty in measurement.