NF EN ISO 6143, X20-207 (06/2025)

This International Standard describes methods for a) determining the composition of a calibration gas mixture by comparison with suitable mixtures of reference gases, b) calculating the uncertainty of the composition of a calibration gas mixture by relative to the known uncertainty in the composition of the reference gas mixtures with which it was compared, c) checking the composition assigned to a calibration gas mixture against appropriate reference gas mixtures, d) comparing the composition of several gas mixtures for calibration, for example to compare different gas mixture preparation methods, or to determine the homogeneity among gas mixtures of similar composition. NOTE In principle, the method described in this document is also applicable to the analysis of (largely) unknown samples rather than calibration gas mixtures of potential interest (i.e. gas mixtures intended to be used as gas mixtures for calibration). However, these applications require special attention and the consideration of additional components of uncertainty, concerning, for example, the effect of matrix differences between the reference gases used for calibration and the analyzed sample.
(Automatic translation from French)