ISO 4259-3:2020 PDF

Scope: This document specifies the methodology for the regular monitoring of the test method precision achieved versus the precision published in the standard test method using data from proficiency testing schemes (PTSs) supported by the regular users of standard test methods. The procedures in this document are designed specifically for proficiency testing (PT) conducted on standard test methods, having a published reproducibility, for petroleum and petroleum-related products, which are presumed to be homogeneous, and where the data distribution is approximately normal. In addition, it is applicable to properties of interest that are (known to be) stable over time and transport. This document specifies the methodology for the statistical comparison of standard deviation under reproducibility conditions achieved in PT programmes versus that published. The purpose of this comparison is to find out if the published reproducibility precision is representative of that achievable by the regular participants in the PT programmes. This document also provides guidance on how to use a PT z-score to monitor an individual participant’s performance over time (see Annex B).

ISO 4259-3:2020 Referenced Document

ISO 13528:2015 Statistical methods for use in proficiency testing by interlaboratory comparison
ISO 4259-1 Petroleum and related products — Precision of measurement methods and results — Part 1: Determination of precision data in relation to methods of test AMENDMENT 1
ISO/IEC 17043 Conformity assessment - General requirements for the competence of proficiency testing providers*， 2023-05-08 Update

2020 ISO 4259-3:2020 Petroleum and related products — Precision of measurement methods and results — Part 3: Monitoring and verification of published precision data in relation to methods of test