# Regulation (EU) No 1007/2011 of the European Parliament and of the Council of 27 September 2011 on textile fibre names and related labelling and marking of the fibre composition of textile products and repealing Council Directive 73/44/EEC and Directives 96/73/EC and 2008/121/EC of the European Parliament and of the Council (Text with EEA relevance), Division III.1: PRECISION OF THE METHODS

Extent: E+W+S+N.I.

The precision indicated in each method of analysis of binary fibre mixtures relates to the reproducibility (see Chapter 2 relating to methods for quantitative analysis of certain binary textile fibre mixtures).
Reproducibility refers to the reliability, i.e. the closeness of agreement between experimental values obtained by operators in different laboratories or at different times using the same method and obtaining individual results on specimens of an identical homogeneous mixture.
Reproducibility is expressed by confidence limits of the results for a confidence level of 95 %.
By this is meant that the difference between two results in a series of analyses made in different laboratories would, given a normal and correct application of the method to an identical and homogeneous mixture, exceed the confidence limit only in five cases out of 100.
To determine the precision of the analysis of a ternary fibre mixture the values indicated in the methods for the analysis of binary fibre mixtures which have been used to analyse the ternary fibre mixture are applied in the usual way.
Given that in the four variants of the quantitative chemical analysis of ternary fibre mixtures, provision is made for two dissolutions (using two separate specimens for the first three variants and a single specimen for the fourth variant) and, assuming that E1 and E2 denote the precision of the two methods for analysing binary fibre mixtures, the precision of the results for each component is shown in the following table:
Component fibre
Variants
1
2 and 3
4
a
E1
E1
E1
b
E2
E1 + E2
E1 + E2
c
E1 + E2
E2
E1 + E2
If the fourth variant is used, the degree of precision may be found to be lower than that calculated by the method indicated above, owing to possible action of the first reagent on the residue consisting of components b and c, which would be difficult to evaluate.

---
Source: https://www.legislation.gov.uk/eur/2011/1007/annex/VIII/chapter/3/division/1/division/III/division/III.1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2011-1007/annex-VIII/chapter-3/division-1/division-III/division-III.1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.