prEN ISO 6974-4

Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 4: Guidance on gas analysis (ISO/DIS 6974-4:2025)

This document gives guidance for obtaining the best analysis results possible from a Gas Chromatograph (GC) when analysing natural gas and natural gas substitutes for combined use with the most recent versions of ISO 6974’s part 1, 2 and 3. (Examples are given.)

Erdgas - Bestimmung der Zusammensetzung und der damit verbundenen Unsicherheit durch Gaschromatographie - Teil 4: Leitfaden für die Gasanalyse

Dieses Dokument enthält einen Leitfaden, wie die bestmöglichen Analyseergebnisse mit einem Gaschromatographen (GC) bei der Analyse von Erdgas und Erdgas-Austauschgasen erhalten werden, und es ist zur gemeinsamen Verwendung mit den neuesten Versionen von ISO 6974, Teile 1, 2 und 3, vorgesehen (es werden Beispiele angeführt).

Gaz naturel - Détermination de la composition avec une incertitude définie par chromatographie en phase gazeuse - Partie 4: Détermination de l'azote, du dioxyde de carbone et des hydrocarbures C1 à C5 et C6+ pour un système de mesurage en laboratoire et en continu employant deux colonnes

Zemeljski plin - Določanje sestave in s tem povezane negotovosti s plinsko kromatografijo - 4. del: Navodilo za analizo plina (ISO/DIS 6974-4:2025)

General Information

• Status: Not Published
• Publication Date: 07-Sep-2026
• ICS: 75.060 - Natural gas
• Technical Committee: CEN/TC 238 - Test gases, test pressures and categories of appliances
• Drafting Committee: CEN/TC 238 - Test gases, test pressures and categories of appliances
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 13-Feb-2025
• Due Date: 13-Feb-2025
• Completion Date: 13-Feb-2025
• Ref Project: oSIST prEN ISO 6974-4:2025 - Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 4: Guidance on gas analysis (ISO/DIS 6974-4:2025)

Relations

• Revises: EN ISO 6974-4:2001 - Natural gas - Determination of composition with defined uncertainty by gas chromatography - Part 4: Determination of nitrogen, carbon dioxide and C1 to C5 and C6+ hydrocarbons for a laboratory and on-line measuring system using two columns (ISO 6974-4:2000)
• Effective Date: 28-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2025
Zemeljski plin - Določanje sestave in s tem povezane negotovosti s plinsko
kromatografijo - 4. del: Navodilo za analizo plina (ISO/DIS 6974-4:2025)
Natural gas - Determination of composition and associated uncertainty by gas
chromatography - Part 4: Guidance on gas analysis (ISO/DIS 6974-4:2025)
Erdgas - Bestimmung der Zusammensetzung und der damit verbundenen Unsicherheit
durch Gaschromatographie - Teil 4: Leitfaden für die Gasanalyse
Gaz naturel - Détermination de la composition avec une incertitude définie par
chromatographie en phase gazeuse - Partie 4: Détermination de l'azote, du dioxyde de
carbone et des hydrocarbures C1 à C5 et C6+ pour un système de mesurage en
laboratoire et en continu employant deux colonnes
Ta slovenski standard je istoveten z: prEN ISO 6974-4
ICS:
75.060 Zemeljski plin Natural gas
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 6974-4
ISO/TC 193/SC 1
Natural gas — Determination
Secretariat: NEN
of composition and
Voting begins on:
associated uncertainty by gas
2025-02-10
chromatography —
Voting terminates on:
2025-05-05
Part 4:
Guidance on gas analysis
ICS: 75.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
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This document is circulated as received from the committee secretariat.
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Reference number
ISO/DIS 6974-4:2025(en)
DRAFT
ISO/DIS 6974-4:2025(en)
International
Standard
ISO/DIS 6974-4
ISO/TC 193/SC 1
Natural gas — Determination
Secretariat: NEN
of composition and
Voting begins on:
associated uncertainty by gas
chromatography —
Voting terminates on:
Part 4:
Guidance on gas analysis
ICS: 75.060
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2025
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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BE CONSIDERED IN THE LIGHT OF THEIR
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Published in Switzerland Reference number
ISO/DIS 6974-4:2025(en)
ii
ISO/DIS 6974-4:2025(en)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 1
5 Overview . 2
6 Sample . 3
6.1 General .3
6.2 Gas origin . . .3
6.3 Phase of sample .4
6.4 Sample pressure .4
6.5 Sampling .4
7 Sample introduction . 5
7.1 General .5
7.2 Sample loop .5
7.2.1 General .5
7.2.2 The temperature of the sample loop .5
7.2.3 The pressure within the loop .5
7.2.4 Sample shut-off before injection .5
7.2.5 The atmospheric pressure effect .6
7.3 Injection .6
7.4 Vacuum injection .8
8 Separation . 8
8.1 General .8
8.2 Columns .9
8.3 Carrier gas .9
8.3.1 Types of gases .9
8.3.2 Carrier gas flowrate .9
8.3.3 Purity of the carrier and auxiliary gas .10
8.4 Temperature .10
8.5 Separation columns .11
8.6 Back-Flush. 12
8.7 Maintenance related to column performance . 12
8.8 Environmental conditions . 12
8.9 General setup . 13
8.10 Correction for the presence of oxygen and argon . 13
8.10.1 General . 13
8.10.2 Gas containing oxygen. . 13
8.10.3 Gas containing argon .14
8.10.4 Air contamination correction for natural gas spot samples .14
8.10.5 Correction when the amount of argon has been determined .14
8.10.6 Correction when the amount of argon has not been determined . 15
9 Detection . 16
9.1 Typical detectors for natural gas analysis .16
9.2 Peak resolution .17
9.3 Detector . 20
10 Data processing .20
10.1 Data . 20
10.1.1 General . 20
10.1.2 Conversion . 20
...