SIST EN 14662-3:2005
(Main)Ambient Air Quality - Standard method for the measurement of benzene concentrations - Part 3: Automated pumped sampling with in situ gas chromatography
Ambient Air Quality - Standard method for the measurement of benzene concentrations - Part 3: Automated pumped sampling with in situ gas chromatography
This part of EN 14662 is in accordance with the generic methodology selected as the basis of the European Union Reference Method for the determination of benzene in ambient air [1] for the purpose of comparison of measurement results with limit values with a one-year reference period.
The standard describes guidelines for measurements with, and type approval of, automated gas chromatographs. The use of automated instruments gives this part a different structure compared to the other parts including the procedure for selecting an appropriate automated gas chromatograph by means of type approval tests.
Requirements for use in the field are also described.
The standard is applicable to measurements of airborne benzene vapour in the concentration range from 0 µg/m3 to 50 µg/m3 (Standardised to 101,3 kPa and 293 K). This concentration range represents the certification range for benzene in the type approval test.
Luftbeschaffenheit - Standardverfahren zur Bestimmung von Benzolkonzentrationen - Teil 3: Automatische Probenahme mit einer Pumpe mit gaschromatographischer In-situ-Bestimmung
Dieser Teil von prEN 14662 ist in Übereinstimmung mit der allgemeinen Methode, die als Grundlage des Referenzverfahrens der Europäischen Union zur Bestimmung von Benzol in Außenluft [1] gewählt wurde, um Messergebnisse mit Grenzwerten auf Basis von Jahresmittelwerten zu vergleichen.
Diese Norm gibt Anleitungen für die Messung mit und die Eignungsprüfung von automatischen Gaschromatographen. Die Verwendung automatischer Geräte gibt diesem Teil, verglichen mit den anderen, einen anderen Aufbau einschließlich Verfahrenskenngrößen, die erforderlich sind, durch Eignungsprüfungen einen geeigneten Gaschromatographen auszuwählen.
Außerdem werden die Anforderungen für die Verwendung im Feld festgelegt.
Die Norm ist anwendbar für Messungen von gasförmigem Benzol in Luft im Konzentrationsbereich von 0,5 µg/m3 bis 50 µg/m3 (normalisiert auf 101,3 kPa und 293 K). Dieser Konzentrationsbereich entspricht dem Konzentrationsbereich für Benzol in den Eignungsprüfungen.
Qualité de l'air ambiant - Méthode normalisée pour le mesurage de la concentration en benzene - Partie 3 : Prélevement par pompage automatique avec analyse chromatographique en phase gazeuse sur site
La présente partie de l’EN 14662 est conforme a la méthodologie générique sélectionnée comme base pour la Méthode de référence de l’Union européenne de détermination du benzene dans l’air ambiant [1], en vue de la comparaison des résultats de mesurage avec des valeurs limites pour une période de référence d’un an.
La présente norme fournit des lignes directrices pour les mesurages avec des chromatographes en phase gazeuse automatiques et pour leur approbation de type. L’utilisation d’instruments automatisés confere a la présente partie une structure différente des autres parties, qui comprend le mode opératoire de sélection d’un chromatographe en phase gazeuse automatisé a l’aide d’essais d’approbation de type.
Les exigences relatives a leur utilisation sur site sont également spécifiées.
La présente norme est applicable aux mesurages de vapeur de benzene en suspension dans l’air dans la gamme de concentrations comprise entre 0,5 mg/m3 et 50 mg/m3 (étalonnée a 101,3 kPa et 293 K). Cette gamme de concentrations représente l’étendue de mesure certifiée pour le benzene lors de l’essai d’approbation de type.
Kakovost zunanjega zraka - Standardna metoda za določevanje koncentracije benzena - 3. del: Avtomatsko vzorčenje s črpanjem in določevanje z in-situ plinsko kromatografijo
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 14662-3:2005
01-september-2005
.DNRYRVW]XQDQMHJD]UDND6WDQGDUGQDPHWRGD]DGRORþHYDQMHNRQFHQWUDFLMH
EHQ]HQDGHO $YWRPDWVNRY]RUþHQMHVþUSDQMHPLQGRORþHYDQMH]LQVLWXSOLQVNR
NURPDWRJUDILMR
Ambient Air Quality - Standard method for the measurement of benzene concentrations -
Part 3: Automated pumped sampling with in situ gas chromatography
Luftbeschaffenheit - Standardverfahren zur Bestimmung von Benzolkonzentrationen -
Teil 3: Automatische Probenahme mit einer Pumpe mit gaschromatographischer In-situ-
Bestimmung
Qualité de l'air ambiant - Méthode normalisée pour le mesurage de la concentration en
benzene - Partie 3 : Prélevement par pompage automatique avec analyse
chromatographique en phase gazeuse sur site
Ta slovenski standard je istoveten z: EN 14662-3:2005
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
SIST EN 14662-3:2005 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN 14662-3:2005
---------------------- Page: 2 ----------------------
SIST EN 14662-3:2005
EUROPEAN STANDARD
EN 14662-3
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2005
ICS 13.040.20
English version
Ambient Air Quality - Standard method for the measurement of
benzene concentrations - Part 3: Automated pumped sampling
with in situ gas chromatography
Qualité de l'air ambiant - Méthode pour le mesurage des Luftbeschaffenheit - Standardverfahren zur Bestimmung
concentrations en benzène - Partie 3 - Echantillonnage par von Benzolkonzentrationen - Teil 3: Automatische
pompage automatique suivi d'une chromatographie en Probenahme mit einer Pumpe mit gaschromatographischer
phase gazeuse in situ In-situ-Bestimmung
This European Standard was approved by CEN on 21 March 2005.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14662-3:2005: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Contents
Foreword .3
1 Scope.4
2 Normative references .4
3 Terms and definitions.4
4 Symbols and abbreviated terms.8
5 Principles.9
6 Reagents and materials.10
7 Apparatus .11
8 Type approval.12
9 Field Operation and Ongoing Quality Control .25
10 Reports and documentation .33
Annex A (normative) Test of lack of fit.35
Annex B (informative) Calculation of uncertainty in field operation at the limit value for
individual measurements .37
Annex C (informative) An example of the results of an inter-calibration exercise.39
Annex D (informative) Components and applications of type approved benzene monitors .42
Bibliography.44
2
---------------------- Page: 4 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Foreword
This European Standard (EN 14662-3:2005) has been prepared by Technical Committee CEN/TC 264
“Air quality”, 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 November 2005, and conflicting national standards
shall be withdrawn at the latest by November 2005.
This document has been prepared under a mandate given to CEN by the European Commission and
the European Free Trade Association, and supports essential requirements of EU Directive
2000/69/EC and EU Directive 96/62 EC.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia,
Spain, Sweden, Switzerland and United Kingdom.
3
---------------------- Page: 5 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
1 Scope
This part of EN 14662 is in accordance with the generic methodology selected as the basis of the
European Union Reference Method for the determination of benzene in ambient air [1] for the purpose
of comparison of measurement results with limit values with a one-year reference period.
The standard describes guidelines for measurements with, and type approval of, automated gas
chromatographs. The use of automated instruments gives this part a different structure compared to
the other parts including the procedure for selecting an appropriate automated gas chromatograph by
means of type approval tests.
Requirements for use in the field are also described.
The standard is applicable to measurements of airborne benzene vapour in the concentration range
3 3
from 0 µg/m to 50 µg/m (Standardised to 101,3 kPa and 293 K). This concentration range represents
the certification range for benzene in the type approval test.
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.
ENV 13005, Guide to the expression of uncertainty in measurement
EN ISO 14956, Air quality - Evaluation of the suitability of a measurement procedure by comparison
with a required measurement uncertainty (ISO 14956:2002)
EN ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories
(ISO/IEC 17025:1999)
ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results - Part 2:
Basic method for the determination of repeatability and reproducibility of a standard measurement
method
ISO 5725-3:1995, Accuracy (trueness and precision) of measurement methods and results - Part 3:
Intermediate measures of the precision of a standard measurement method
ISO 6142: 2001 Gas analysis – Preparation of calibration gas mixtures - Gravimetric method
ISO 6143 Gas analysis – Determination of the composition of calibration gas mixtures – Comparison
methods
ISO 6144 Gas analysis - Preparation of calibration gas mixtures - Static volumetric method
ISO 6145 (all parts) Gas analysis - Preparation of calibration gas mixtures - Dynamic volumetric
methods
3 Terms and definitions
For the purposes of this European Standard the following terms and definitions apply.
3.1
Ambient air
outdoor air in the troposphere
4
---------------------- Page: 6 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
3.2
Ambient temperature
temperature at the sample inlet outside the monitoring station
3.3
Availability of the analyser
fraction of the total time period for which valid measuring data of the ambient air concentration is
available
3.4
Calibration
comparison of the analyser response to a known gas concentration with a known uncertainty
3.5
Carry-over (memory effect)
influence of the previous measurement due to the retention of benzene within the instrument
3.6
Certification range
concentration range for which the analyser is type approved
3.7
Combined standard uncertainty
calculation result of combining the standard uncertainties calculated from all performance
characteristics specified in this standard according to the prescribed procedure given in this standard
3.8
Designated body
body (which can be a laboratory) which has been designated for a specific task (type approval tests
and/or QA/QC activities in the field) by a competent authority in the Member States
NOTE It is recommended that the designated body is accredited for the specific task according to EN
ISO/IEC 17025
3.9
Detection limit
lowest concentration level in ambient air for which the instrument does not give a zero response
3.10
Expanded uncertainty
for the purposes of this standard, the combined uncertainty of the measurement multiplied by a factor
of 2 and so expressed with a level of confidence of 95 %
3.11
Independent measurement
individual measurement that is not influenced by a previous individual measurement
3.12
Individual measurement
measurement averaged over a time period equal to the sampling time
3.13
Influence quantity
quantity that affects the result of a measurement
3.14
Interference
response of the analyser to interferents
5
---------------------- Page: 7 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
3.15
Interferent
single gaseous component in the sampled air, other than benzene, that affects the output signal of the
analyser
3.16
International (measurement) standard
standard recognised by an international agreement to serve internationally as the basis for assigning
values to other standards of the quantity concerned
3.17
Lack of fit
deviation of the average of a series of measurements at the same concentration from the linear
regression line
3.18
Limit value
concentration level fixed on the basis of scientific knowledge, with the aim of avoiding, preventing or
reducing harmful effects on human health, as stated in the EU legislation
3.19
Linearity
ability of a series of data to be modelled by a linear regression line
3.20
Long term drift
change in zero or span readings over the period of unattended operation
3.21
Measurand
particular quantity subject to measurement. For the purpose of this EN-standard it is benzene in air
3.22
Monitoring station
enclosure located in the field in which an automated benzene-analyser has been installed in such a
way that its performance and operation complies with the prescribed requirements
3.23
Operational range
concentration range for which the analyzer is calibrated. It shall not exceed the certification range
3.24
Parallel measurement
two measurements from different analysers, sampling from one and the same sampling manifold
starting at the same time and ending at the same time
3.25
Performance characteristic
one of the parameters assigned to equipment in order to define its performance, e.g. linearity
3.26
Performance criterion
limiting quantitative numerical value assigned to a performance characteristic, to which conformance is
tested
3.27
Repeatability (of results of measurement)
closeness of the agreement between the results of successive measurements of the same measurand
carried out under the same conditions of measurement [2]
6
---------------------- Page: 8 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
NOTE 1 These conditions are called laboratory repeatability conditions and include:
- the same measurement procedure;
- the same analyser, used under the same conditions;
- at the same location;
- repetition over a short period of time;
- the same observer.
NOTE 2 In this EN-standard the repeatability is expressed as a value with a level of confidence of 95 %.
3.28
Response time
time interval between the instant when a stimulus is subjected to a specified abrupt change and the
instant when the response reaches and remains within specified limits around its final steady value.
NOTE For the analyzers described in this Standard, that perform measurements integrated over a certain
time period, the response time is at least one measurement cycle.
3.29
Reproducibility under field conditions
closeness of the agreement between the results of parallel measurements with two analysers in
ambient air carried out under the same conditions of measurement
NOTE 1 These conditions are called field reproducibility conditions and include:
- the same measurement procedure;
- two identical analysers, used under the same conditions;
- at the same monitoring station;
- the period of unattended operation.
NOTE 2 In this EN-standard the reproducibility under field conditions is expressed as a value with a level of
confidence of 95 %
3.30
Sampled air
ambient air that has been sampled through the sampling inlet and sampling system
3.31
Sampling inlet
entrance to the sampling system where the ambient air is collected from the atmosphere
3.32
Short term drift
change in zero or span measurement results over a 24 hour period
3.33
Sorbent
materials that can collect benzene from sample air with near 100 % efficiency and release it again by
heating in a flow of a carrier gas e.g. nitrogen, helium or hydrogen
3.34
Standard uncertainty
uncertainty of the result of a measurement expressed as a standard deviation [ENV 13005:1999]
3.35
Temperature of surrounding air
temperature of the air directly surrounding the analyser, ie the temperature inside the monitoring
station or laboratory
3.36
Transfer standard
working standard that is routinely used to calibrate or check measuring instruments and is traceable to
an international standard and can be moved (transferred) from place to place
7
---------------------- Page: 9 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
3.37
Type approval
decision taken by a designated laboratory that the pattern of an analyser conforms to the requirements
as laid down in this EN-standard (comparable to the "pattern approval" as described by the OIML [4])
3.38
Type approval test
examination of two or more analysers of the same pattern which are submitted by a manufacturer to a
designated body; this examination includes the test necessary for approval of the pattern (comparable
to "pattern evaluation" as described by the OIML [4])
3.39
Uncertainty
parameter associated with the result of a measurement that characterises the dispersion of the values
that could reasonably be attributed to the measurand
4 Symbols and abbreviated terms
A intercept of the calibration function
A availability of the analyser
a
B slope of the calibration function
bj sensitivity coefficient of c for influence quantity xj at C = ctest
c measured value of the measurand
ctest value of the measurand at which the required measurement uncertainty is given
c average value of individual measurements of the measurand
d drift of measured value on input quantity Yi at C = ctest
E collection efficiency of sample system
ss
i index of input quantities Y
j index of influence quantities X
k coverage factor
n total number of input quantities; last number
m total number of influence quantities
p index of the performance characteristic
pmax maximum number of performance characteristics considered
r Repeatability
s(xj) standard deviation of xj at C = ctest
t0,95 95 percentile of the t-distribution
Uc combined expanded uncertainty of c at C = ctest expressed as a 95 % confidence interval
8
---------------------- Page: 10 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
uc combined standard uncertainty of c at C = ctest
u partial standard uncertainty of c due to repeatability of input quantity Yi at yi
r
corresponding to C = ctest
u partial standard uncertainty of c due to reproducibility of input quantity Yi at yi
R
corresponding to C = ctest
u standard uncertainty of input quantity Yi
x jth influence quantity
j
X lack of fit
l
y individual measurand
i
Y carry over or memory effect of measurand
5 Principles
A measured volume of sample air is drawn or forced through a sorbent tube. Provided suitable
sorbents are chosen, benzene is retained by the sorbent tube and thus is removed from the flowing air
stream. The collected benzene (on each tube) is desorbed by heat and is transferred by inert carrier
gas into a gas chromatograph equipped with a capillary column and a flame ionisation detector or
other suitable detector, where it is analysed. Prior to entering the column the sample is concentrated
either on a cryo trap, which is heated to release the sample into the column, or on a pre-column,
where higher boiling hydrocarbons are removed from the pre-column by back flush.
Two general types of instruments are used. One is equipped with a single sampling trap and the other
is equipped with two or more traps. The single trap instrument samples for only part of the time in
each cycle whereas the multitrap instrument samples continuously as illustrated in Figures 1 and 2
respectively. Typical cycling times are between 15 minutes and 1 hour.
Figure 1 sampling by single trap
9
---------------------- Page: 11 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Figure 2 sampling by multitrap
6 Reagents and materials
6.1 Measurement standards of Benzene
Standard atmospheres of known concentrations of benzene shall be prepared by recognised
procedures as described in ISO 6142, ISO 6144 and ISO 6145. If the procedure is not applied under
conditions that will allow the establishment of full traceability of the generated concentrations to
standards of mass or volume, or if the chemical inertness of the generation system cannot be
guaranteed, the concentrations need to be confirmed using an independent procedure or a reference
gas traceable to national standard.
The concentrations of measurement standard atmospheres shall have an expanded uncertainty of
less than 5%.
An internationally accepted certified matrix reference material may also be used.
6.2 Transfer standard/span gas
A transfer standard is needed for quality control to check the regular function of the analyser and to
allow correction of drift. The concentration needs to be known but traceability can be obtained from the
standard atmospheres of 6.1. The benzene concentration should be between 70% and 90% of the
certification range. Transfer standards have to be stable during the period of usage.
The concentrations of transfer standard atmospheres shall have an expanded uncertainty of less than
7,5%.
Methods for transfer standard preparation are listed in Table 1.
10
---------------------- Page: 12 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Table 1 - Methods for preparation of transfer standards
Method Description Traceability/
Standard to be used
Gravimetry Gas cylinder with a content of benzene in the range 70%-90% of the ISO 6142
certification range ISO 6143
Permeation tubes Mass loss of benzene from a permeable tube into a zero air stream ISO 6145-10
Dynamic dilution Dynamic blending of cylinder gas containing high benzene ISO 6145-7
concentration (mg/m³) with zero air
Diffusion Mass loss of benzene from a diffusion tube into a zero air stream ISO 6145-8
NOTE Practical examples of the application of these methods, with performance characteristics, are
described in VDI 2100 Part 4 [5].
6.3 Zero air
Zero air shall have a content of benzene lower than the detection limit and can be provided either as
synthetic air from a cylinder or from a compressor followed by an air purifier system.
NOTE The chromatograms of zero air samples provide a check of the benzene content. Where available an
independent measurement method should be used for purity analysis.
7 Apparatus
Some typical automated gas chromatograph systems, with their operational parameters for trapping,
focusing trap/pre-column, capillary column and detectors are listed in Annex D.
The following equipment is also needed.
7.1 Calibration facility
Calibration standards shall be traceable to internationally accepted standards and meet the
requirements of 6.1 and 6.2.
7.2 Sample inlet, sample line and filter
The sampling line and the residence time of the sample shall be as short as practicable. The line and
the filter shall be chemically inert to benzene, made of a material such as glass, stainless steel or Per-
Fluoro-Carbon (FEP or PFA). Calibration or span gases shall be used to test the inertness of the
complete sampling train. The influence of the sample line, filter and inlet shall be less than 2% of the
signal output of the analyser at a concentration close to the Limit Value.
NOTE The sample line may need to be moderately heated to avoid condensation of water. Condensation
may occur in the case of high ambient temperature and/or humidity.
11
---------------------- Page: 13 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
8 Type approval
8.1 Introduction
Type approval of an analyser requires provision of evidence that the requirements concerning data
quality specified by the applicable EU Directive, 2000/69/EU, will be met when the analyser is used in
all conditions typical of its intended use.
Type approval testing, by designated bodies, is the quantified assessment of the performance
characteristics given in this standard as necessary to achieve a measurement uncertainty less than or
equal to the required uncertainty.
The performance characteristics are to be assessed by tests carried out in the laboratory with two
identical analysers, and in the field (monitoring site) with at least two identical analysers of the same
type out of one series. Both analysers are required to pass the test and all results shall be reported.
Appropriate experimental evidence shall be provided by
- type approval test results, and
- calculation of measurement uncertainty by reference to ENV 13005, to ISO 5725-2 or to both
documents.
8.2 Performance characteristics and performance criteria determined in laboratory
tests
The laboratory tests consist of the determination of the performance characteristics stated in Table 2,
according to the procedures described in 8.5.
NOTE It is recommended that the designated body for the type approval test shall be accredited for these
activities according to EN ISO/IEC 17025.
12
---------------------- Page: 14 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Table 2 - Relevant performance characteristics and performance criteria determined in
laboratory test
*No. Performance characteristics Symbol Paragraph **Performance
criterion
1 Lack of fit, largest residual X 8.5.3 < ± 5 %
l
3 3
2 Repeatability at 0,5 µg/m r 8.5.5 < ± 0,3 µg/m
(0,5)
3 Repeatability at limit value r 8.5.5 < ± 5 %
(LV)
4 Influence of the interference from ozone 8.5.9.1 < ± 5 %
b
O
3
5 Influence of the interference from sum of 8.5.9.3 < ± 5 %
b
C
org
possible interfering organic compounds at span
value
6 Influence of the interference from relative 8.5.9.2 < ± 4 %.
b
rh
humidity
7 Sensitivity coefficient for the influence of 8.5.7 < ± 0,2 %/K
b
Ts
surrounding temperature at span value
8 Sensitivity coefficient for the influence of 8.5.6 < ± 1 %/kPa
b
p
ambient pressure at span value
9 Sensitivity coefficient for the influence of 8.5.8 < ± 0,2 %/V
b
V
voltage at span value
10 Short term drift (24 hours) at span value 8.5.4 < ± 5 %
d
24h
12 Carry over Y 8.5.10 < 10 % of the limit
value for the first
analysis after the
response time
* Nos. 1 and 3-9 are used in calculation of combined uncertainty of a measured value
** Where the performance criterion is expressed as a percentage, the test value shall be calculated as 100 u/C, where u is the
-3
uncertainty component in µg m , as determined in the paragraph indicated in the table, and C is the highest benzene
-3
concentration used for the test, in µg m
8.3 Type approval assessment
For the purpose of type approval the analysers tested shall fulfil the following requirements:
a) each individual performance characteristic shall fulfil the criteria in Table 2 (laboratory tests) and
Table 5 (field tests, Section 8.6).
b) the expanded measurement uncertainty calculated from the combination of all performance
characteristics shall be less than the maximum allowable uncertainty prescribed in the relevant
Directive.
Sections 8.5.3 to 8.5.10 describe the laboratory type approval tests that determine the performance
criteria shown in Table 2. Performance characteristics noted in Table 2 (laboratory tests) and Table 5
(field tests) shall be included in the calculation of expanded uncertainty.
13
---------------------- Page: 15 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
8.4 Changes in design
The manufacturer shall report any design change to a previously type approved monitor, including
software changes, to the competent authority. The underlying purpose of the design change and the
expected consequences with respect to the performance characteristics, as stated in Table 2 and
Table 5, shall be reported by the manufacturer. The competent authority [3] shall decide whether new
tests are necessary or not.
Changes to the following are excluded from this requirement:
- Materials in the instrument frame (housing);
- electronic connectors and slots;
- bolts, nuts, cable binders and other fixing materials.
8.5 Procedures for determining performance characteristics during laboratory tests,
and calculation of the standard uncertainties
8.5.1 Introduction
A designated body shall perform the determination of the performance characteristics in the laboratory
as a part of the type approval test. The quality of the materials and equipment used in the test
procedures shall be in accordance with the requirements given in this standard. The laboratory tests
shall be performed on two analysers.
8.5.2 Test conditions
8.5.2.1 General
Before operating the analyser, the manufacturer’s operating instructions shall be followed, particularly
with regard to installation, and the quality and quantity of necessary consumable items.
Before any tests are performed, the warm-up time specified by the manufacturer shall be taken into
account. If the warm-up time is not specified, a minimum of two hours shall be assumed.
All tests shall be performed in a time schedule that is as short as possible, to minimise the influence of
drift and changes in ambient conditions.
When applying test gases to the analyser, the test gas system shall be operated for a sufficient time to
stabilise the concentration.
8.5.2.2 Accommodation and environmental conditions
The laboratory shall ensure that environmental conditions such as ambient temperature and power
supply do not adversely affect the quality of any results.
The environmental conditions and all test conditions shall be monitored, controlled and recorded as
required by the relevant specifications.
Limiting conditions for the laboratory type approval tests are given in Table 6, in section 8.8.
8.5.2.3 Calibration gases
Several laboratory tests require calibration gases (air containing a known amount of benzene) to be
used. These shall be traceable to national standards unless otherwise stated in this EN-standard.
Various methods for the generation of calibration gases are given in Table 3.
14
---------------------- Page: 16 ----------------------
SIST EN 14662-3:2005
EN 14662-3:2005 (E)
Table 3 - Methods for preparation of primary calibration gases
Method Description Traceability/
Standard to be used
Gravimetry Gas cylinder with a content of benzene in the range of a few ppb ISO 6142
Permeation tubes Determination of the weight loss of a permeable tube containing ISO 6145-10
benzene
Static dilution Preparation by means of injecti
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.