EN ISO 14912:2025
(Main)Gas analysis - Conversion of gas mixture composition data (ISO 14912:2025)
Gas analysis - Conversion of gas mixture composition data (ISO 14912:2025)
This document defines the following quantities commonly used to express the composition of gas mixtures:
— amount fraction and concentration;
— mass fraction and concentration;
— volume fraction and concentration.
For these quantities of composition, this document specifies methods for:
— conversion between different quantities;
— conversion between different state conditions.
Conversion between different quantities means calculating the value of the content of a specified component in terms of one of the quantities listed above from the value of the same content, at the same pressure and temperature of the gas mixture, given in terms of another of these quantities. Conversion between different state conditions means calculating the value of the content of a specified component, in terms of one of the quantities listed above, under one set of state conditions from the value of the same quantity under another set of state conditions, i.e., pressure and temperature, of the gas mixture. Gas mixture composition can be converted simultaneously between different quantities of composition and different state conditions by combination of the two types of conversion.
This document is applicable only to homogeneous and stable gas mixtures. Therefore, any state conditions (pressure and temperature) considered need to be well outside the condensation region of the gas mixture. In addition, volume concentrations can only be used if the component under consideration is completely gaseous, and for the use of volume fractions, all components need to be completely gaseous. Further restrictions of state conditions apply for approximations of compression factors using virial coefficients (see Annex A).
Gasanalyse - Umrechnung von Zusammensetzungsangaben für Gasgemische (ISO 14912:2025)
Dieses Dokument definiert die folgenden Größen, die zur Angabe der Zusammensetzung von Gasgemischen verwendet werden:
Stoffmengenanteil und Stoffmengenkonzentration;
Massenanteil und Massenkonzentration;
Volumenanteil und Volumenkonzentration.
Für diese Zusammensetzungsgrößen legt dieses Dokument Verfahren fest zur:
Umrechnung zwischen verschiedenen Größen;
Umrechnung zwischen verschiedenen Zustandsbedingungen.
Umrechnung zwischen verschiedenen Größen bedeutet Berechnung des Werts des Gehalts einer festgelegten Komponente in einer der oben genannten Größen aus dem Wert desselben Gehalts, gegeben in einer anderen dieser Größen, bei gleichem Druck und gleicher Temperatur des Gasgemischs. Umrechnung zwischen verschiedenen Zustandsbedingungen bedeutet Berechnung des Werts des Gehalts einer festgelegten Komponente in einer der oben genannten Größen bei einem Satz von Zustandsbedingungen aus dem Wert derselben Größe bei einem anderen Satz von Zustandsbedingungen, d. h. Druck und Temperatur, des Gasgemischs. Durch Kombination dieser beiden Umrechnungsarten kann die Zusammensetzung von Gasgemischen zugleich zwischen verschiedenen Zusammensetzungsgrößen und verschiedenen Zustandsbedingungen umgerechnet werden.
Dieses Dokument ist nur bei homogenen und stabilen Gasgemischen anwendbar. Deshalb müssen die betrachteten Zustandsbedingungen (Druck und Temperatur) mit deutlichem Abstand außerhalb des Kondensationsgebiets des Gasgemischs liegen. Zusätzlich können Volumenkonzentrationen ausschließlich dann verwendet werden, wenn die betreffende Komponente vollständig gasförmig ist, und bei der Verwendung von Volumenanteilen müssen sogar alle Komponenten vollständig gasförmig sein. Weitere Einschränkungen der Zustandsbedingungen gelten für Näherungen von Realgasfaktoren durch Virialkoeffizienten (siehe Anhang A).
Analyse des gaz - Conversion des données de composition de mélanges gazeux (ISO 14912:2025)
Le présent document définit les grandeurs suivantes qui sont couramment utilisées pour exprimer la composition des mélanges gazeux:
— fraction et concentration molaires;
— fraction et concentration massiques;
— fraction et concentration volumiques.
Pour ces grandeurs de composition, le présent document spécifie des méthodes permettant:
— une conversion entre différentes grandeurs;
— une conversion entre différentes conditions d’état.
La conversion entre différentes grandeurs implique de calculer la valeur de la teneur d’un constituant spécifié, selon les termes de l’une des grandeurs précitées, à partir de la valeur de la même teneur, aux mêmes pression et température du mélange de gaz, exprimée dans une autre de ces grandeurs. La conversion entre différentes conditions d’état implique de calculer la valeur de la teneur d’un constituant spécifié, selon les termes de l’une des grandeurs précitées, dans un ensemble de conditions d’état, à partir de la valeur de la même grandeur dans un autre ensemble de conditions d’état, c’est-à-dire d’autres pression et température, du mélange gazeux. La composition d’un mélange gazeux peut être simultanément convertie entre différentes grandeurs de composition et différentes conditions d’état, en combinant les deux types de conversion.
Le présent document s’applique uniquement aux mélanges gazeux homogènes et stables. Par conséquent, toute condition d’état (pression et température) considérée doit se situer bien en dehors de la région de condensation du mélange gazeux. De plus, les concentrations volumiques ne peuvent être utilisées que si le constituant examiné est entièrement gazeux et, en cas d’utilisation de fractions volumiques, tous les constituants doivent être entièrement gazeux. D’autres restrictions des conditions d’état s’appliquent pour les approximations de facteurs de compressibilité utilisant des coefficients du viriel (voir Annexe A).
Analiza plinov - Pretvorba podatkov o sestavi plinskih zmesi (ISO 14912:2025)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2025
Nadomešča:
SIST EN ISO 14912:2006
SIST EN ISO 14912:2006/AC:2008
Analiza plinov - Pretvorba podatkov o sestavi plinskih zmesi (ISO 14912:2025)
Gas analysis - Conversion of gas mixture composition data (ISO 14912:2025)
Gasanalyse - Umrechnung von Zusammensetzungsangaben für Gasgemische (ISO
14912:2025)
Analyse des gaz - Conversion des données de composition de mélanges gazeux (ISO
14912:2025)
Ta slovenski standard je istoveten z: EN ISO 14912:2025
ICS:
71.040.40 Kemijska analiza Chemical analysis
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 14912
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2025
EUROPÄISCHE NORM
ICS 71.040.40 Supersedes EN ISO 14912:2006, EN ISO
14912:2006/AC:2007
English Version
Gas analysis - Conversion of gas mixture composition data
(ISO 14912:2025)
Analyse des gaz - Conversion des données de Gasanalyse - Umrechnung von
composition de mélanges gazeux (ISO 14912:2025) Zusammensetzungsangaben für Gasgemische (ISO
14912:2025)
This European Standard was approved by CEN on 8 May 2025.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14912:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 14912:2025) has been prepared by Technical Committee ISO/TC 158 "Analysis
of gases" in collaboration with Technical Committee CEN/TC 238 “Test gases, test pressures, appliance
categories and gas appliance types” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2025, and conflicting national standards
shall be withdrawn at the latest by November 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 14912:2006.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 14912:2025 has been approved by CEN as EN ISO 14912:2025 without any modification.
International
Standard
ISO 14912
Second edition
Gas analysis — Conversion of gas
2025-05
mixture composition data
Analyse des gaz — Conversion des données de composition de
mélanges gazeux
Reference number
ISO 14912:2025(en) © ISO 2025
ISO 14912:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
ISO 14912:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 Quantities for the expression of gas mixture composition .2
3.2 Additional quantities involved in conversions of gas mixture composition .3
4 Symbols and units. 4
5 Basic Principles . 6
5.1 Expression of gas mixture composition.6
5.2 Conversion between different quantities .7
5.3 Conversion between different state conditions .9
6 Main procedures . 9
6.1 Conversion between different quantities of composition .9
6.1.1 Conversion of the content of single components .9
6.1.2 Conversion of complete compositions .10
6.2 Conversion to reference conditions .11
7 Practical implementation.12
7.1 Conversion between quantities of composition . 12
7.2 Conversion of single contents . . 13
7.3 Conversion of complete compositions . 13
7.4 Conversion between state conditions .14
7.5 Simple approximations applicable to conversion .14
7.5.1 Ideal mixture of ideal gases .14
7.5.2 Ideal mixture of real gases .14
7.5.3 Trace gas mixture . 15
8 Input quantities and their uncertainties .15
8.1 Pure gas data . 15
8.1.1 Molar mass . 15
8.1.2 Compression factor . 15
8.2 Gas mixture data .17
8.2.1 Molar mass .17
8.2.2 Compression factor .18
8.2.3 Mixing factor . 20
8.3 Rough uncertainty estimates .21
9 Conversion uncertainty .21
9.1 General considerations.21
9.2 Conversion of single contents . . 22
9.3 Conversion of complete compositions . 23
9.4 Variances and covariances of input composition data . 25
9.4.1 General procedure . 25
9.4.2 Correlation effects in complete composition data . 25
Annex A (informative) Assessment of state conditions .28
Annex B (informative) Summation relations for the expression of mixture properties .31
Annex C (informative) Mixture component data.32
Annex D (informative) Examples .38
Annex E (informative) Computer implementation of recommended methods.
...
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