BS ISO 7504:2015 pdf free.Gas analysis一Vocabulary. BS ISO 7504 defines terms related to gas analysis, with the main locus on terms related to calibration gas mixtures for use in gas analysis and gas measurements. It does not cover terms which relate only to specific applications. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) lSO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and associated terms (ViM) ISO 10715:1997, Natural gas — Sampling guidelines 3 Terms relating to general concepts Terms used in the field of gas analysis that are well defined by either ISO/IEC Guide 98-3 or ISO/IEC Guide 99 are included in Annex A. 3.1 homogeneity state of a gas mixture wherein all of its components (13) are distributed uniformly throughout the volume occupied by the gas mixture 3.2 stability attribute of a gas mixture, under specified conditions, to maintain its…