SIST EN ISO 6974-1:2001

Natural gas - Determination of composition with defined uncertainty by gas chromatography - Part 1: Guidelines for tailored analysis (ISO 6974-1:2000)

Migrated from Progress Sheet (TC Comment) (2000-07-10): WIs 020-025 = result of the splitting of WI 011 (CC/991102 at the request of ++ R. R{migy and A. Pirlet)

Erdgas - Bestimmung der Zusammensetzung mit definierter Unsicherheit durch Gaschromatographie - Teil: Richtlinien für die maßgeschneiderte Analyse (ISO 6974-1:2000)

Dieser Teil von ISO 6974 gibt Richtlinien für die quantitative Analyse von Erdgaskomponenten innerhalb des in Tabelle 1 angegebenen Anwendungsbereichs.
Die einzelnen Verfahren, wie sie in Teil 3 und den folgenden Teilen von ISO 6974 beschrieben sind, können eingeschränktere Anwendungsbereiche als die in Tabelle 1 angegebenen haben, aber in allen Fällen werden sie im Gesamtanwendungsbereich der angegebenen Grenzen liegen.
Tabelle 1 - Anwendungsbereiche
Komponente   Molfraktionsbereich
%
Wasserstoff   0,001 bis 0,5
Helium   0,001 bis 0,5
Sauerstoff   0,001 bis 5
Stickstoff   0,001 bis 60
Kohlenstoffdioxid   0,001 bis 35
Methan   40 bis 100
Ethan   0,02 bis 15
Propan   0,001 bis 25
Butane   0,0001 bis 5
Pentane   0,0001 bis 1
Hexane und höhere   0,0001 bis 0,5

Gaz naturel - Détermination de la composition avec une incertitude définie par chromatographie en phase gazeuse - Partie 1: Lignes directrices pour l'analyse spéciale (ISO 6974-1:2000)

L'ISO 6974-1:2000 donne les lignes directrices pour l'analyse quantitative des constituants du gaz naturel dans les limites des gammes d'application indiquées au Tableau 1 de l'ISO 6974-1:2000.

Zemeljski plin - Določevanje sestave z določeno negotovostjo s plinsko kromatografijo - 1. del: Navodila za specialne analize (ISO 6974-1:2000)

General Information

• Status: Withdrawn
• Publication Date: 30-Nov-2001
• Withdrawal Date: 05-Jun-2012
• ICS: 75.060 - Natural gas
• Technical Committee: NAD - Petroleum products, lubricants and related products
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 05-Jun-2012
• Due Date: 28-Jun-2012
• Completion Date: 06-Jun-2012
• Ref Project: EN ISO 6974-1:2001 - Natural gas - Determination of composition with defined uncertainty by gas chromatography - Part 1: Guidelines for tailored analysis (ISO 6974-1:2000)

Relations

• Replaced By: SIST EN ISO 6974-1:2012 - Natural gas - Determination of composition and associated uncertainty by gas chromatography - Part 1: General guidelines and calculation of composition (ISO 6974-1:2012)
• Effective Date: 01-Jul-2012

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 6974-1:2001
01-december-2001
=HPHOMVNLSOLQ'RORþHYDQMHVHVWDYH]GRORþHQRQHJRWRYRVWMRVSOLQVNR
NURPDWRJUDILMRGHO1DYRGLOD]DVSHFLDOQHDQDOL]H,62
Natural gas - Determination of composition with defined uncertainty by gas
chromatography - Part 1: Guidelines for tailored analysis (ISO 6974-1:2000)
Erdgas - Bestimmung der Zusammensetzung mit definierter Unsicherheit durch
Gaschromatographie - Teil: Richtlinien für die maßgeschneiderte Analyse (ISO 6974-
1:2000)
Gaz naturel - Détermination de la composition avec une incertitude définie par
chromatographie en phase gazeuse - Partie 1: Lignes directrices pour l'analyse spéciale
(ISO 6974-1:2000)
Ta slovenski standard je istoveten z: EN ISO 6974-1:2001
ICS:
75.060 Zemeljski plin Natural gas
SIST EN ISO 6974-1:2001 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 6974-1:2001

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SIST EN ISO 6974-1:2001
EUROPEAN STANDARD
EN ISO 6974-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2001
ICS 75.060
English version
Natural gas - Determination of composition with defined
uncertainty by gas chromatography - Part 1: Guidelines for
tailored analysis (ISO 6974-1:2000)
Gaz naturel - Détermination de la composition avec une Erdgas - Bestimmung der Zusammensetzung mit
incertitude définie par chromatographie en phase gazeuse definierter Unsicherheit durch Gaschromatographie - Teil:
- Partie 1: Lignes directrices pour l'analyse spéciale (ISO Richtlinien für die maßgeschneiderte Analyse (ISO 6974-
6974-1:2000) 1:2000)
This European Standard was approved by CEN on 22 June 2001.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6974-1:2001 E
worldwide for CEN national Members.

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SIST EN ISO 6974-1:2001
EN ISO 6974-1:2001 (E)
CORRECTED  2002-03-13
Foreword
The text of the International Standard from Technical Committee ISO/TC 193 "Natural gas" of
the International Organization for Standardization (ISO) has been taken over as a European
Standard by CMC.
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 February 2002, and conflicting national
standards shall be withdrawn at the latest by February 2002.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 6974-1:2000 has been approved by CEN as a
European Standard without any modifications.
NOTE Normative references to International Standards are listed in annex ZA (normative).
2

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SIST EN ISO 6974-1:2001
EN ISO 6974-1:2001 (E)
Annex ZA
(normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of
any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated
by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 6974-3 2000 Natural gas - Determination of EN ISO 6974-3 2001
composition with defined
uncertainty by gas chromatography
- Part 3: Determination of hydrogen,
helium, oxygen, nitrogen, carbon
dioxide and hydrocarbons up to C8
using two packed columns
ISO 6974-4 2000 Natural gas - Determination of EN ISO 6974-4 2001
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 6974-5 2000 Natural gas - Determination of EN ISO 6974-5 2001
composition with defined
uncertainty by gas chromatography
- Part 5: Determination of nitrogen,
carbon dioxide and C1 to C5 and
C6+ hydrocarbons for a laboratory
and on-line process application
using three columns
ISO 10715 1997 Natural gas - Sampling guidelines EN ISO 10715 2000
3

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SIST EN ISO 6974-1:2001

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SIST EN ISO 6974-1:2001
INTERNATIONAL ISO
STANDARD 6974-1
First edition
2000-04-01
Natural gas — Determination of
composition with defined uncertainty by
gas chromatography —
Part 1:
Guidelines for tailored analysis
Gaz naturel — Détermination de la composition avec une incertitude
définie par chromatographie en phase gazeuse —
Partie 1: Lignes directrices pour l'analyse spéciale
Reference number
ISO 6974-1:2000(E)
©
ISO 2000

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
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ii © ISO 2000 – All rights reserved

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Symbols and subscripts .4
5 Principles of analysis .4
6 Materials .5
7 Apparatus .5
8 Required characteristics.6
9 Sampling.6
10 Analytical procedure .6
11 Methods of test .8
12 Control chart .10
13 Uncertainty in the mole fraction of the normalized components .10
14 Test report .10
Annex A (informative) Comparative characteristics of typical analytical methods, as described in parts
3 to 6 of ISO 6974.12
Annex B (informative) Use of control charts .13
Bibliography.16
© ISO 2000 – All rights reserved iii

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 6974 may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 6974-1 was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee
SC 1, Analysis of natural gas.
This part as well as the other five parts of ISO 6974 cancel and replace ISO 6974:1984 which specified only one
method.
ISO 6974 consists of the following parts, under the general title Natural gas — Determination of composition with
defined uncertainty by gas chromatography :
— Part 1: Guidelines for tailored analysis
— Part 2: Measuring-system characteristics and statistics for data treatment
— Part 3: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C using
8
two packed columns
— Part 4: Determination of nitrogen, carbon dioxide and C to C and C hydrocarbons for a laboratory and on-
1 5 6+
line measuring system using two columns
— Part 5: Determination of nitrogen, carbon dioxide and C to C and C hydrocarbons for a laboratory and on-
1 5 6+
line process application using three columns
— Part 6: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C using
8
three capillary columns
Annexes A and B of this part of ISO 6974 are for information only.
iv © ISO 2000 – All rights reserved

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
Introduction
This part of ISO 6974 gives guidelines for the "tailored" analysis of natural gas with the aim of determining the mole
fractions of the principal components.
ISO 6974 (all parts) describes methods of analysis of natural gas with definable levels of uncertainty. The approach
is suitable for the calculation of calorific value and other additive physical properties of the gas, again with a
definable uncertainty.
Part 2 of ISO 6974 describes the determination of the measuring system characteristics and the statistical
approach to data handling and error calculation with the aim of defining the uncertainties in the component mole
fractions.
Part 3 and subsequent parts of ISO 6974 describe different possible methodologies for tailored analyses, which
can only be applied in conjunction with parts 1 and 2 of ISO 6974.
Parts 1 and 2 represent the body of ISO 6974. The method chosen from Part 3 and subsequent parts or from any
other source requires compliance with parts 1 and 2 of ISO 6974.
Informative annex A gives a comparison of the characteristics of typical analytical methods as described in part 3
and subsequent parts of ISO 6974.
ISO 6974 (all parts) is designed for the measurement of H ,He, O ,N ,CO , individual hydrocarbons and/or a
2 2 2 2
total figure for hydrocarbons for example above C defined as C �. It is not applicable to other minor components
5 6
where their contribution to physical properties is not significant or can be regarded as constant. Among these are
potentially natural components such as Ar, H O and sulfur compounds, and components arising from gas treatment
2
such as methanol, glycols and amines.
The described method allows air contamination in the sample to be recognized and measured in the case of spot
sampling and laboratory analysis, but not necessarily for on-line analysis.
Although "tailored" analysis itself is relatively simple, it can produce an analysis with high accuracy, provided that
elaborate preparations are carried out. These include outlining the structure of the analysis, defining the working
ranges and establishing the analytical procedure. However, in practice, only a limited number of steps are
necessary for setting up the method to meet the requirements for specific application. The amount of work and
calculations necessary will then be relatively restricted.
This part of ISO 6974 describes all the essential steps for setting up a "tailored" analysis.
Assuming that the analytical results follow the normal distribution, control charts give an indication as to whether
the measuring system and the established method is working satisfactorily. For this reason the use of control charts
is described in informative annex B of this part of ISO 6974.
ISO 6974 (all parts) can be used in daily practice in a laboratory and for on-line field applications and covers the
following options or alternatives.
� Straight-line or polynomial calibration plots.
� Single-point or multi-level calibration.
� Recombination of components by backflushing to vent, recombination of components by backflushing to
measure, or forward elution of all components.
� Calibration one-to-one, or by relative response factors to a reference component.
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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
� The use of a thermal conductivity detector (TCD) is necessary and in certain cases a flame ionisation detector
(FID) may be used in addition.
When setting up a tailored analysis, a series of choices are to be made from these options. The consequences of
the combination chosen should be assessed. The procedure for this assessment is described in this part of
ISO 6974. If the assessment shows that the performance is poorer than desired, another combination can be
chosen, in which case the assessment is to be repeated in full.
vi © ISO 2000 – All rights reserved

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SIST EN ISO 6974-1:2001
INTERNATIONAL STANDARD ISO 6974-1:2000(E)
Natural gas — Determination of composition with defined
uncertainty by gas chromatography —
Part 1:
Guidelines for tailored analysis
1 Scope
This part of ISO 6974 gives guidelines for the quantitative analysis of natural-gas-containing constituents within the
application ranges given in Table 1.
Individual methods, as described in part 3 and subsequent parts of ISO 6974, may have more restricted application
ranges than those in Table 1, but in all cases they will fall within this overall scope of the ranges given.
Table 1 — Application ranges
Mole fraction range
Component
%
Hydrogen 0,001 to 0,5
Helium 0,001 to 0,5
Oxygen 0,001 to 5
Nitrogen 0,001 to 60
Carbon dioxide 0,001 to 35
Methane 40 to 100
Ethane 0,02 to 15
Propane 0,001 to 25
Butanes 0,000 1 to 5
Pentanes 0,000 1 to 1
Hexanes and heavier 0,000 1 to 0,5
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 6974. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 6974 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 6974-2, Natural gas — Determination of composition with defined uncertainty by gas chromatography —
Part 2: Measuring-system characteristics and statistics for data treatment.
ISO 6974-3, Natural gas — Determination of composition with defined uncertainty by gas chromatography —
Part 3: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C using two
8
packed columns.
© ISO 2000 – All rights reserved 1

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
ISO 6974-4, Natural gas — Determination of composition with defined uncertainty by gas chromatography —
Part 4: Determination of nitrogen, carbon dioxide and C to C and C hydrocarbons for a laboratory and on-line
1 5 6+
measuring system using two columns.
ISO 6974-5, Natural gas — Determination of composition with defined uncertainty by gas chromatography —
Part 5: Determination of nitrogen, carbon dioxide and C to C and C hydrocarbons for a laboratory and on-line
1 5 6+
process application using three columns.
ISO 6974-6, Natural gas — Determination of composition with defined uncertainty by gas chromatography —
Part 6: Determination of hydrogen, helium, oxygen, nitrogen, carbon dioxide and hydrocarbons up to C using three
8
capillary columns.
ISO 6975, Natural gas — Extended analysis — Gas-chromatographic method.
ISO 10715, Natural gas — Sampling guidelines.
3 Terms and definitions
For the purposes of this part of ISO 6974, the following terms and definitions apply.
3.1
response
output signal of the measuring system for a component that is measured as peak area or peak height, expressed in
counts
3.2
reference component
component present in a working-reference gas mixture (WRM) (see 3.9), which is used to calibrate the analyser
response to other, similar components in the sample which are not themselves present in the working-reference
gas mixture
NOTE For example, if the WRM contains hydrocarbons up to and including n-butane, but no pentanes or higher, then
n-butane contained in the WRM can be used as a reference component for the quantification of pentanes and heavier
components in the sample. The reference component should have a response function which normally is a first-order
polynomial with zero intercept, i.e. a straight line through the origin.
3.3
relative response factor
K
j
ratio of the molar amount of component j to the molar amount of reference component which gives an equal
detector response
3.3.1
relative response factor for flame ionisation detector (FID)
calculated as the ratio of the carbon number of the reference component to the carbon number of the sample
component
NOTE The values of the relative response factors are described in ISO 6974-2.
3.3.2
relative response factor for thermal conductivity detector (TCD)
determined using reference gas mixtures as described in ISO 6974-2
3.4
other components
components in the gas sample which are not measured by tailored analysis in accordance with ISO 6974 (all parts)
and/or can be regarded as being present at a constant mole fraction
2 © ISO 2000 – All rights reserved

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
NOTE The mole fraction of these components, except methanol and sulfur, can be determined by extended analysis in
accordance with ISO 6975.
3.5
group of components
components with mole fractions so low that their measurement as individuals would be difficult or require excessive
time, and which are measured as a group
NOTE This can be achieved by particular chromatographic techniques, such as backflushing, or by data handling, such as
integrating a succession of components as if they were a single component.
3.6
accuracy
closeness of agreement between a measurement result and the true value of the measurand
NOTE The term accuracy, when applied to a set of measurement results, describes a combination of random components
and a common systematic error or bias component.
3.7
uncertainty
estimate attached to a measurement result which characterizes the range of values within which the true value is
asserted to lie
NOTE In general, the uncertainty of measurements comprises many components. Some of these components may be
estimated on the basis of statistical distribution of the results of series of measurements and can be characterized by
experimental standard deviation (SD). The estimates of other components can only be based on experience or other
information.
3.8
certified-reference gas mixtures
CRM
mixtures which are used for the determination of the response curves of the measuring system
[1] [2]
NOTE Certified-reference gas mixtures may be prepared gravimetrically in accordance with ISO 6142 or ISO 13275 or
certified and validated by comparison with primary standard gas mixtures of closely related composition in accordance with
[3] [4]
ISO 6143 (see ISO 14111 ).
3.9
working-reference gas mixtures
WRM
mixtures which are used as working standards for regular calibration of the measuring system
[1]
NOTE Working-reference gas mixtures may be prepared by a gravimetric method in accordance with ISO 6142 or
[3]
certified and validated by comparison with CRM of closely related composition in accordance with ISO 6143 .
3.10
direct measurement
measurement by which individual components and/or groups of components are determined by comparison with
identical components in the working-reference gas mixture
3.11
indirect measurement
measurement by which individual components and/or groups of components which are themselves not present in
the working-reference gas mixture are determined using relative response factors to a reference component in the
working-reference gas mixture
3.12
repeatability
value below which the absolute difference between two single measurement results obtained using the same
method, on identical measurement material, by the same operator, using the same apparatus, in the same
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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
laboratory, within a short interval of time, (repeatability conditions), may be expected to lie with a specified
probability; in absence of other indication the probability is 95 %
3.13
control gas
high-pressure gas mixture of known composition containing all the components present in the working-reference
gas mixture
[3]
NOTE 1 A control gas can be either a gas sample with a composition determined in accordance with ISO 6143 or a
[1] [2]
multicomponent mixture prepared in accordance with ISO 6142 or ISO 13275 . A control gas is used to calculate the mean
(�� and the standard deviation (�) of component mole fractions detected for the preparation of the relevant control charts.
NOTE 2 For on-line analysis the working-reference gas mixture may be used as a control gas.
3.14
working range
restricted mole fraction range within the application range of Table 1, that is specific for methods of tailored
analysis
4 Symbols and subscripts
4.1 Symbols
a ,b ,c ,d polynomial constants of component j
j j j j
K ratio of the response factor of component j to the response factor of the reference component
j
R response expressed as the number of counts
x normalized mole fraction
*
x non-normalized mole fraction
4.2 Subscripts
c air contamination
j component j
mc main components to be analysed using direct measurement
oc components which are not measured and/or can be regarded as being present at a constant mole
fraction
rcwrm reference component of the working-reference gas mixtures
rrf components or groups of components to be analysed using indirect measurement
ssample
wrm working-reference gas mixture
5Principlesofanalysis
All significant components or groups of components to be determined in a gaseous sample are physically
separated by means of gas chromatography and measured by comparison with calibration data obtained under the
4 © ISO 2000 – All rights reserved

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
same set of conditions. Therefore the calibration gas(es) and the gas sample shall be analysed with the same
measuring system under the same set of conditions. The mole fraction of non-measured components can influence
the accuracy of the method and shall therefore be known.
After the working ranges of all components are defined, an evaluation shall be carried out to define which
components are to be considered
� as components or groups of components to be analysed using direct measurement against identical
components or groups in the working-reference gas mixture (x ),
mc
� as components or groups of components to be analysed using indirect measurement against a different
reference component in the working-reference gas mixture (x ), and
rrf
� as other components which are not to be measured, and whose mole fraction can be assumed to be constant
(x ).
oc
The sum of the mole fractions of components measured directly and indirectly, as well as other components is
equal to 1 as follows:
x � x � x =1
mc rrf oc
6 Materials
6.1 Certified-reference gas mixture (CRM), consisting of components the mole fractions of which cover the
working range (see 10.2.1, step 1) and which are used for the determination of the response curve of the
measuring system.
Depending upon the working range and the accuracy required, more than one CRM may be needed.
The working range shall not necessarily cover the whole application range of this part of ISO 6974.
6.2 Working-reference gas mixture (WRM), consisting of components, the mole fractions of which have a
value situated within the working range to which the working reference applies.
The WRM shall contain all those components that are measured by direct comparison.
7 Apparatus
7.1 Measurement system, comprising a sample introduction and transfer unit, a separation unit, a detection
unit, an integrator and a data reduction system.
Part 3 and subsequent parts of ISO 6974 give different configurations of laboratory and on-line measuring system
which have been found to be suitable.
NOTE Annex A summarizes the comparative characteristics of parts 3 to 6 of ISO 6974.
© ISO 2000 – All rights reserved 5

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SIST EN ISO 6974-1:2001
ISO 6974-1:2000(E)
8 Required characteristics
For the gas sample to be analysed with a definable level of uncertainty, the analytical procedure shall satisfy the
following characteristics:
� the gas to
...