EN 838:2010

SLOVENSKI STANDARD
01-april-2010
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SIST EN 838:1998
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Workplace exposure - Procedures for measuring gases and vapours using diffusive
samplers - Requirements and test methods
Exposition am Arbeitsplatz - Messung von Gasen und Dämpfen mit Diffusionssammlern -
Anforderungen und Prüfverfahren
Exposition sur les lieux de travail - Procédures pour le mesurage des gaz et vapeurs à
l'aide de dispositifs de prélèvement par diffusion - Exigences et méthodes d'essai
Ta slovenski standard je istoveten z: EN 838:2010
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 838
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2010
ICS 13.040.30 Supersedes EN 838:1995
English Version
Workplace exposure - Procedures for measuring gases and
vapours using diffusive samplers - Requirements and test
methods
Exposition sur les lieux de travail - Procédures pour le Exposition am Arbeitsplatz - Messung von Gasen und
mesurage des gaz et vapeurs à l'aide de dispositifs de Dämpfen mit Diffusionssammlern - Anforderungen und
prélèvement par diffusion - Exigences et méthodes d'essai Prüfverfahren
This European Standard was approved by CEN on 11 December 2009.

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, Croatia, 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: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 838:2010: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Symbols and abbreviations .5
5 Types of samplers .7
6 Requirements .7
6.1 General .7
6.2 Sampler requirements .8
6.3 Measuring procedure requirements .9
7 General test conditions . 11
7.1 Reagents . 11
7.2 Apparatus . 11
7.3 Independent method . 12
7.4 Generation of a calibration gas mixture . 12
8 Test methods . 13
8.1 General . 13
8.2 Sampler test methods . 13
8.3 Measuring procedure test methods . 16
8.4 Uncertainty of measurement . 21
9 Test report . 23
Annex A (informative) Fundamentals of diffusive sampling. 24
Annex B (informative) Estimation of uncertainty of measurement . 26
Annex C (informative) Example of estimation of expanded uncertainty . 36
Bibliography . 39

Foreword
This document (EN 838:2010) has been prepared by Technical Committee CEN/TC 137 “Assessment of
workplace exposure to chemical and biological agents”, the secretariat of which is held by DIN.
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 July 2010, and conflicting national standards shall be withdrawn at the
latest by July 2010.
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.
This document supersedes EN 838:1995.
The major technical changes between this European Standard and the previous edition are as follows:
a) adaptation of the framework for assessing the performance of procedures for measuring gases and
vapours against the general requirements for the performance of procedures for measuring chemical
agents in workplace atmospheres as specified in EN 482;
b) revision of the calculation model for the uncertainty of measurement to comply with EN 482 and
ENV 13005;
c) modification of the classification scheme for sampler types;
d) deletion of the informative annexes on the evaluation of diffusive samplers by means of field tests.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Introduction
This European Standard provides a framework for assessing the performance of procedures for measuring
gases and vapours against the general requirements for the performance of procedures for measuring
chemical agents in workplace atmospheres as specified in EN 482. These performance criteria include
maximum values of expanded uncertainty achievable under prescribed laboratory conditions for the methods
to be used. In addition, the performance criteria should also be met under a wider variety of environmental
influences, representative of workplace conditions.
This European Standard enables manufacturers and users of diffusive samplers and developers and users of
procedures for measuring gases and vapours to adopt a consistent approach to method validation.
1 Scope
This European Standard specifies performance requirements and test methods under prescribed laboratory
conditions for the evaluation of diffusive samplers and of procedures using these samplers for the
determination of gases and vapours in workplace atmospheres.
This European Standard is applicable to diffusive samplers and measuring procedures using these samplers
in which sampling and analysis are carried out in separate stages.
This European Standard is not applicable to:
 diffusive samplers which are used for the direct determination of concentrations;
 diffusive samplers which rely on sorption into a liquid.
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.
EN 482:2006, Workplace atmospheres ― General requirements for the performance of procedures for the
measurement of chemical agents
EN 1076, Workplace exposure ― Procedures for measuring gases and vapours using pumped samplers ―
Requirements and test methods
EN 1540, Workplace atmospheres ― Terminology
EN ISO 8655-2, Piston-operated volumetric apparatus ― Part 2: Piston pipettes (ISO 8655-2:2002)
EN ISO 8655-6, Piston-operated volumetric apparatus ― Part 6: Gravimetric methods for the determination of
measurement error (ISO 8655-6:2002)
3 Terms and definitions
1)
For the purposes of this document, the terms and definitions given in EN 482:2006 and EN 1540 apply.
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
NOTE See 8.4 and Annex C for symbols used in conjunction with uncertainty of measurement only.
A cross-sectional area of sorption surface, in square centimetres (cm²)
CRM certified reference material

1) EN 1540:1998 is currently subject to revision. Until the revised EN is published the definitions given in EN 482:2006
take precedence.
D diffusion coefficient of an analyte, in square centimetres per minute (cm²/min)

a
D diffusion coefficient of analyte 1, in square centimetres per minute (cm²/min)

a1
D diffusion coefficient of analyte 2, in square centimetres per minute (cm²/min)

a2
l length of static air layer in sampler (or equivalent for permeation types), in centimetres (cm)
LV limit value
m mass of analyte desorbed from blank sampler, in nanograms (ng)

b
m mass of analyte desorbed, in nanograms (ng)
d
m mass of the analyte which can diffuse to a suitable sorbent within a certain time, i.e. the mass uptake

s
of a diffusive sampler, in nanograms (ng)
m& mass loss from permeation tube, in micrograms per minute (µg/min)
M molar mass of analyte, in grams per mole (g/mol)
a
n number of replicate samples
p    actual pressure of the test atmosphere sampled, in kilopascals (kPa)
at
R recovery
R analytical recovery
an
RH relative humidity of the test atmosphere sampled, in percent (%)

t exposure time, in minutes (min)

e
T temperature of the test atmosphere sampled, in Kelvin (K)
at
&
U uptake rate, in cubic centimetres per minute (cm³/min)
d
-1 -1
&
(U )' uptake rate, in nanograms per parts per million (volume fraction) per minute (ng ppm min )
d
&
U uptake rate of analyte 1, in cubic centimetres per minute (cm³/min)
d1
&
U uptake rate of analyte 2, in cubic centimetres per minute (cm³/min)
d2
&
v flow rate into the exposure chamber, for example, in litres per minute (l/min)
β mass concentration of the analyte in the calibration gas mixture, in milligrams per cubic metre

a
(mg/m³)
(β )' mass concentration in parts per million (ppm);
a
β mass concentration of the given analyte at the beginning of the diffusion layer (i.e. at the distance l

a1
from the surface of the sorbent), in milligrams per cubic metre (mg/m³)
β mass concentration of the given analyte at the end of the diffusion layer (i.e. at the surface of the

a2
sorbent), in milligrams per cubic metre (mg/m³)
β mean mass concentration of the analyte recovered from the test gas atmosphere, in milligrams per
a,R
cubic metre (mg/m³);
β mass concentration of the calibration gas mixture, in milligrams per cubic metre (mg/m³)

cg
ϑ temperature of the test atmosphere sampled, in degree Celsius (°C)
at
2)
Κ coefficient of variation (CV)

v
φ volume fraction of the analyte, in microlitres per litre (µl/l)

a
5 Types of samplers
Samplers for gases and vapours can be divided into type A samplers and type B samplers:
Type A samplers rely on sorption onto a solid or onto a support impregnated with a reagent, desorption with
solvent, and subsequent analysis of the desorbate. They are usually made of glass and c
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