EN ISO 4259:2006

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Stages in the planning of an inter-laboratory test
   programme for the determination of the precision of
   a test method
   4.1 General
   4.2 Preparing a draft method of test
   4.3 Planning a pilot programme with at least two
       laboratories
   4.4 Planning the inter-laboratory programme
   4.5 Executing the inter-laboratory programme
5 Inspection of inter-laboratory results for uniformity
   and for outliers
   5.1 General
   5.2 Transformation of data
   5.3 Tests for outliers
   5.4 Rejection of complete data from a sample
   5.5 Estimating missing or rejected values
   5.6 Rejection test for outlying laboratories
   5.7 Confirmation of selected transformation
6 Analysis of variance, calculation and expression of
   precision estimates
   6.1 General
   6.2 Analysis of variance
   6.3 Expectation of mean squares and calculation of
       precision estimates
   6.4 Expression of precision estimates of a method of test
7 Significance of repeatability (r) and reproducibility (R)
   7.1 General
   7.2 Repeatability, r
   7.3 Reproducibility, R
8 Specifications
   8.1 Aim of specifications
   8.2 Construction of specifications limits in relation
       to precision
9 Quality control against specifications
   9.1 General
   9.2 Testing margin at the supplier
   9.3 Testing margin at the recipient
10 Dispute procedure
Annex A (normative) Determination of number of samples
                      required
Annex B (informative) Derivation of equation for calculating
                      the number of samples required
Annex C (normative) Notation and tests
Annex D (normative) Example results of test for determination
                      of bromine number and statistical tables
Annex E (normative) Types of dependence and corresponding
                      transformations
Annex F (normative) Weighted linear regression analysis
Annex G (normative) Rules for rounding off results
Annex H (informative) Explanation of equations given in Clause 7
Annex I (informative) Specifications that relate to a specified
                      degree of criticality
Bibliography

ISO 4259:2006 covers the calculation of precision estimates and their application to specifications. In particular, it contains definitions of relevant statistical terms, the procedures to be adopted in the planning of an inter-laboratory test programme to determine the precision of a test method, the method of calculating the precision from the results of such a programme, and the procedure to be followed in the interpretation of laboratory results in relation both to precision of the test methods and to the limits laid down in specifications.The procedures in ISO 4259:2006 have been designed specifically for petroleum and petroleum-related products, which are normally homogeneous. However, the procedures described in this International Standard can also be applied to other types of homogeneous products. Careful investigations are necessary before applying ISO 4259:2006 to products for which the assumption of homogeneity can be questioned.