EN ISO 6145-8:2008

Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 8: Diffusion method (ISO 6145-8:2005)

ISO 6145-8:2005 specifies a dynamic method using diffusion for the preparation of calibration gas mixtures containing component mole fractions ranging from 10-9 to 10-3. A relative expanded uncertainty of measurement, U, obtained by multiplying the relative combined standard uncertainty by a coverage factor k = 2, of not greater than ± 2 % can be achieved by using this method.
By keeping the path between the diffusion source and place of use as short as possible, the method can be applied for the generation of low-concentration calibration gases of organic components that are liquid at room temperature, with boiling points ranging from about 40 °C to 160 °C.
ISO 6145-8:2005 is applicable not only for the generation of calibration gas mixtures of a wide range of hydrocarbons at ambient and indoor air concentration levels, but also for the generation of low-concentration gas mixtures of water.

Gasanalyse - Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-volumetrischen Verfahren - Teil 8: Diffusionsverfahren (ISO 6145-8:2005)

Dieser Teil der ISO 6145 legt ein dynamisches Verfahren zur Herstellung von Kalibriergasgemischen mit
Stoffmengenanteilen der Komponenten im Bereich von 10-9 bis 10-3 fest. Mit diesem Verfahren lässt sich eine
relative erweiterte Messunsicherheit U, bestimmt durch Multiplikation der relativen kombinierten Standardunsicherheit
mit einem Überdeckungsfaktor k = 2, von 2 % oder besser erreichen.
Wird der Weg zwischen der Diffusionsquelle und der Kalibriergasaufgabe so kurz wie möglich gehalten, so
kann das Verfahren zur Erzeugung von Kalibriergasen im niedrigen Konzentrationsbereich mit organischen
Komponenten, die bei Raumtemperatur flüssig sind, mit Siedepunkten von etwa 40 ºC bis 160 ºC verwendet
werden.
Der Anwendungsbereich dieses Teils der ISO 6145 umfasst nicht nur die Herstellung von Kalibriergasgemischen
mit einer Vielzahl von Kohlenwasserstoffen auf Außenluft- und Innenraumluft-Konzentrationsniveau
sondern auch die Erzeugung von Gasgemischen mit Wasser in niedrigen Konzentrationsbereichen.

Analyse des gaz - Préparation des mélanges de gaz pour étalonnage à l'aide de méthodes volumétriques dynamiques - Partie 8: Méthode par diffusion (ISO 6145-8:2005)

L'ISO 6145-8:2005 spécifie une méthode dynamique par diffusion pour la préparation de mélanges de gaz pour étalonnage, dont la teneur en fractions molaires est comprise entre 10-9 et 10-3. En appliquant cette méthode, il est possible d'obtenir une incertitude relative élargie du mesurage, U, obtenue par multiplication de l'incertitude type relative composée par un facteur d'élargissement k = 2, de ± 2 % au maximum.
En maintenant la distance entre la source de diffusion et le lieu d'utilisation aussi courte que possible, la méthode peut être appliquée pour générer des gaz pour étalonnage à faible concentration de composants organiques liquides à température ambiante, les points d'ébullition étant compris entre 40 °C et 160 °C environ.
L'ISO 6145-8:2005 ne s'applique pas uniquement à la génération des mélanges de gaz pour étalonnage d'un large éventail d'hydrocarbures aux niveaux de concentration de l'air ambiant et d'intérieur, mais également à la génération de mélanges de gaz de faible concentration en eau.

Analiza plinov - Priprava kalibracijske plinske zmesi z uporabo dinamičnih volumetričnih metod - 8. del: Difuzijska metoda (ISO 6145-8:2005)

General Information

• Status: Published
• Publication Date: 19-Aug-2008
• ICS: 71.040.40 - Chemical analysis
• 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: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 20-Aug-2008
• Due Date: 28-Sep-2009
• Completion Date: 20-Aug-2008
• Ref Project: SIST EN ISO 6145-8:2008 - Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods - Part 8: Diffusion method (ISO 6145-8:2005)

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2008
$QDOL]DSOLQRY3ULSUDYDNDOLEUDFLMVNHSOLQVNH]PHVL]XSRUDERGLQDPLþQLK
YROXPHWULþQLKPHWRGGHO'LIX]LMVNDPHWRGD,62
Gas analysis - Preparation of calibration gas mixtures using dynamic volumetric methods
- Part 8: Diffusion method (ISO 6145-8:2005)
Gasanalyse - Herstellung von Kalibriergasgemischen mit Hilfe von dynamisch-
volumetrischen Verfahren - Teil 8: Diffusionsverfahren (ISO 6145-8:2005)
Analyse des gaz - Préparation de mélanges de gaz pour étalonnage à l'aide de
méthodes volumétriques - Partie 8: Méthode par diffusion (ISO 6145-8:2005)
Ta slovenski standard je istoveten z: EN ISO 6145-8:2008
ICS:
71.040.40 Kemijska analiza Chemical analysis
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN ISO 6145-8
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2008
ICS 71.040.40
English Version
Gas analysis - Preparation of calibration gas mixtures using
dynamic volumetric methods - Part 8: Diffusion method (ISO
6145-8:2005)
Analyse des gaz - Préparation des mélanges de gaz pour Gasanalyse - Herstellung von Kalibriergasgemischen mit
étalonnage à l'aide de méthodes volumétriques Hilfe von dynamisch-volumetrischen Verfahren - Teil 8:
dynamiques - Partie 8: Méthode par diffusion (ISO 6145- Diffusionsverfahren (ISO 6145-8:2005)
8:2005)
This European Standard was approved by CEN on 30 July 2008.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, 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
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6145-8:2008: E
worldwide for CEN national Members.

Contents Page
Foreword.3

Foreword
The text of ISO 6145-8:2005 has been prepared by Technical Committee ISO/TC 158 “Analysis of gases” of
the International Organization for Standardization (ISO) and has been taken over as EN ISO 6145-8:2008 by
Technical Committee CEN/SS N21 “Gaseous fuels and combustible gas” the secretariat of which is held 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 2009, and conflicting national standards shall be withdrawn
at the latest by February 2009.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 6145-8:2005 has been approved by CEN as a EN ISO 6145-8:2008 without any modification.

INTERNATIONAL ISO
STANDARD 6145-8
First edition
2005-02-01
Gas analysis — Preparation of calibration
gas mixtures using dynamic volumetric
methods —
Part 8:
Diffusion method
Analyse des gaz — Préparation de mélanges de gaz pour étalonnage à
l'aide de méthodes volumétriques —
Partie 8: Méthode par diffusion

Reference number
ISO 6145-8:2005(E)
©
ISO 2005
ISO 6145-8:2005(E)
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ii © ISO 2005 – All rights reserved

ISO 6145-8:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope. 1
2 Normative references . 1
3 Principle . 1
4 Reagents and materials. 2
5 Apparatus. 3
6 Procedure. 4
6.1 Preliminary checks and operating conditions . 4
6.2 Determination of mass loss . 5
7 Expression of results. 6
7.1 Calculation. 6
7.2 Sources of uncertainty . 7
Annex A (informative) Practical example of a diffusion cell calibrator configured for evaluating
speed of response in a hygrometer . 10
Annex B (informative) Example of performances of diffusion cells for toluene and
trichloromethane. 13
Annex C (informative) Example of uncertainty calculations for a periodic weighing system. 15
Bibliography . 19

ISO 6145-8:2005(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 2.
The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 6145-8 was prepared by Technical Committee ISO/TC 158, Analysis of gases.
ISO 6145 consists of the following parts, under the general title Gas analysis — Preparation of calibration gas
mixtures using dynamic volumetric methods:
 Part 1: Methods of calibration
 Part 2: Volumetric pumps
 Part 4: Continuous syringe injection method
 Part 5: Capillary calibration devices
 Part 6: Critical orifices
 Part 7: Thermal mass-flow controllers
 Part 8: Diffusion method
 Part 9: Saturation method
 Part 10: Permeation method
 Part 11: Electrochemical generation
iv © ISO 2005 – All rights reserved

ISO 6145-8:2005(E)
Introduction
This part of ISO 6145 is one of a series of International Standards that present various dynamic volumetric
methods used for the preparation of calibration gas mixtures. In the lower part of the mole fraction range
considered, it is difficult to prepare and maintain gas mixtures – for example of certain organic or reactive
components – in cylinders. This dynamic method has the advantage of a practically unlimited supply of
calibration component, whereby adsorption effects can be reduced or even eliminated.
If the complementary gas flow is measured as a gas mass flow, the preparation of calibration gas mixtures
using diffusion is a dynamic-gravimetric method which gives contents in mole fractions. Principles for the
measurement of the complementary gas flow are given in ISO 6145-1.

INTERNATIONAL STANDARD ISO 6145-8:2005(E)

Gas analysis — Preparation of calibration gas mixtures using
dynamic volumetric methods —
Part 8:
Diffusion method
1 Scope
This part of ISO 6145 specifies a dynamic method using diffusion for the preparation of calibration gas
−9 −3
mixtures containing component mole fractions ranging from 10 to 10 . A relative expanded uncertainty of
measurement, U, obtained by multiplying the relative combined standard uncertainty by a coverage factor
k = 2, of not greater than ± 2 % can be achieved by using this method.
By keeping the path between the diffusion source and place of use as short as possible, the method can be
applied for the generation of low-concentration calibration gases of organic components that are liquid at room
temperature, with boiling points ranging from about 40 °C to 160 °C.
This part of ISO 6145 is applicable not only for the generation of calibration gas mixtures of a wide range of
hydrocarbons at ambient and indoor air concentration levels, but also for the generation of low-concentration
gas mixtures of water.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 6145-7, Gas analysis — Preparation of calibration gas mixtures using dynamic volumetric methods —
Part 7: Thermal mass-flow controllers
3 Principle
The calibration component migrates by diffusion through a diffusion tube of suitable dimensions (length,
diameter) into a flow of a complementary gas, i.e. the complementary gas of the mixture prepared. The liquid
calibration component, of a known high purity, is contained in a reservoir that acts as the source of the
component vapour. The reservoir is provided with a vertically placed diffusion tube. This assembly (the
diffusion cell) is placed in a temperature-controlled containment that is purged at a known and constant flow
rate by a high-p
...