This International Standard specifies a method for the preparation of calibration gas mixtures by a static
volumetric method and provides a procedure for calculating the volumetric composition of the mixture. It can
be used either with binary gas mixtures (containing one calibration component in a complementary gas, which
is usually nitrogen or air[1, 2]) or with mixtures containing more than one component in the complementary gas.
This International Standard also specifies how the expanded uncertainty in the volume fraction of each
calibration component in the mixture is determined by a rigorous evaluation of all the measurement
uncertainties involved, including those associated with the apparatus used for the preparation of the gas
mixture and those associated with the experimental procedure itself.
NOTE 1 This International Standard is generally applicable to the preparation of calibration gas mixtures containing
calibration components in the concentration range 10 × 10 (10 ppb parts per billion) to 50 × (50 ppm parts per million) by volume. However, gas mixtures may be prepared at larger or smaller volume fractions, provided that the components used in the static dilution process are selected appropriately.
NOTE 2 A relative expanded uncertainty of not greater than ± 1 % at a level of confidence of 95 % may be achievable at these concentrations, provided that: the purities of the parent gases have been determined by analysis and any significant impurities and the uncertainties in their measured concentrations have been taken into account; no significant adsorption effects or chemical reactions occur between the gaseous constituents and the internal
surfaces of the apparatus, and there are no reactions between any of the gaseous components, i.e. between the calibration component and complementary gas or between the calibration components themselves;
all the relevant apparatus used in the prepa (...ab (...abbreviated)
Die vorliegende ÖNORM legt ein Verfahren zur Herstellung von Prüfgasen mittels eines volumetrisch-statischen Verfahrens fest und stellt ein Verfahren zur Berechnung der volumetrischen Zusammensetzung des entsprechenden Gasgemisches vor. Es kann entweder mit Binärgasgemischen verwendet werden (die eine Beimengung in einem Grundgas enthalten, üblicherweise Stickstoff oder Luft[1, 2]) oder mit Gemischen, die mehr als eine Beimengung im Grundgas enthalten. Diese ÖNORM legt außerdem fest, wie die erweiterte Unsicherheit im Volumenanteil einer jeden Beimengung im Gemisch durch ausführliche Bewertung sämtlicher Messunsicherheiten bestimmt wird, einschließlich der Unsicherheiten der für die Herstellung des Gasgemisches verwendeten Apparatur und der Unsicherheiten der Versuchsdurchführung selbst.