Analysis of steels and irons - Internal laboratory procedure for checking the accuracy of an analytical method by using Certified Reference Materials
The present statistical procedure describes how to check results for absence of bias by comparison of these analytical results with those obtained during the certification of CRMs.If the resulting data confirm the absence of bias, the method may be considered accurate when applied to all steels and irons whose composition ranges are adequately covered or bounded by the CRMs used.The resulting data give also an estimate of the repeatability and/ or the intermediate precision (" intralaboratory reproducibility" ) for the CRMs used. The comparison of these analytical data with the repeatability data obtained during the certification may also be performed depending on the strict purpose of the method under consideration.NOTE 1 For the purpose of this Technical Report, the use of existing CRMs is essential for the assessment of the trueness, but it may be only indicative for the other statistical data.NOTE 2 This Technical Report does not describe the use of CRMs as calibrants, this subject being treated in ISO Guide 32.
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