SIST-TP CEN/TR 18076:2024

SLOVENSKI STANDARD
01-september-2024
Zunanji zrak - Ekvivalentnost avtomatskih meritev elementarnega ogljika (EC) in
organskega ogljika (OC) v delcih PM
Ambient air - Equivalence of automatic measurements of elemental carbon (EC) and
organic carbon (OC) in PM
Außenluft - Äquivalenz von automatischen Messungen von elementarem Kohlenstoff
(EC) und organischem Kohlenstoff (OC) in PM
Air ambiant - Equivalence des systèmes automatisés de mesurage du carbone
élémentaire et du carbone organique
Ta slovenski standard je istoveten z: CEN/TR 18076:2024
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TR 18076
TECHNICAL REPORT
RAPPORT TECHNIQUE
June 2024
TECHNISCHER REPORT
ICS 13.040.20
English Version
Ambient air - Equivalence of automatic measurements of
elemental carbon (EC) and organic carbon (OC) in PM
Air ambient - Équivalence des mesurages Außenluft - Äquivalenz von automatischen Messungen
automatiques du carbone élémentaire (EC) et du von elementarem Kohlenstoff (EC) und organischem
carbone organique (OC) dans la matière particulaire Kohlenstoff (OC) in PM

This Technical Report was approved by CEN on 10 June 2024. It has been drawn up by the Technical Committee CEN/TC 264.

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, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 18076:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 6
5 Potential automatic candidate methods . 6
5.1 Online thermal analyses . 6
5.2 OC and EC determination . 6
5.3 TC determination . 7
5.4 Photoacoustic spectrometry [11]. 7
5.5 Photo-Thermal Interferometry [13] . 8
5.6 Extinction minus scattering . 8
5.7 Filter-based absorption photometry . 8
5.8 Laser-induced incandescence spectrometry [12] . 9
5.9 Filter-based absorption photometry with high temperature heated inlet . 9
5.10 Online Aerosol Mass Spectroscopy . 10
6 Discussion . 10
7 Uncertainties . 11
7.1 General. 11
7.2 EC . 11
7.3 OC . 12
8 Suggestions for testing the equivalency of candidate methods with EN 16909 . 12
8.1 General. 12
8.2 Sampling . 13
8.3 Type testing . 13
8.4 Field operation and QA/QC . 14
Bibliography . 15
European foreword
This document (CEN/TR 18076:2024) has been prepared by Technical Committee CEN/TC 264 “Air
quality”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
Introduction
The Directive on ambient air quality and cleaner air for Europe [1] requires the chemical speciation of
the sub-2,5 µm size fraction of suspended particulate matter (PM ) in ambient air, as described in
2,5
Annex IV. For air quality to be assessed on a consistent basis across the European Union, Member States
are required to employ standard measurement techniques and procedures. The aim of the European
Standard EN 16909 is to present guidance on the measurement procedures to be followed when
monitoring elemental carbon (EC) and organic carbon (OC) by collecting PM on filters, and
2,5
subsequently performing thermal-optical analyses.
Although EC and OC are only defined in an operational way, measurements according to EN 16909 are
reproducible and EC and OC as defined by the standard are commonly applicable variables. But the
measurement is time consuming, and automated online measurements of EC and OC is not part of
EN 16909. Substitution of OC and EC thermal-optical analyses as described in EN 16909 by automatic
methods would be useful, if the equivalence of candidate methods with the standard EN 16909 can be
demonstrated.
1 Scope
This document provides definitions of the quantities measured by various candidate methods, their basic
principles, and their advantages and disadvantages.
Currently no traceable primary reference materials are available for EC and OC analyses. This document
provides guidance to test the equivalence between candidate methods and EN 16909 for EC and/or OC
determination(s), based on EN 16450.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 16909:2017, Ambient air — Measurement of elemental carbon (EC) and organic carbon (OC) collected
on filters
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 16909:2017 and the following
apply.
3.1
notional limit value
limit values for EC and OC estimated from WHO Guideline recommendation for PM 24 h average limit
2,5
value (15 µg/m ) [2] and the average concentration of EC and OC observed in Europe at such level of
PM concentration
2,5
3.2
Black Carbon
BC
carbonaceous component of particulate matter that absorbs light in all wavelengths of solar radiation
present in the troposphere, i.e. 280 nm to 2500 nm
3.3
Equivalent Black Carbon
EBC
black carbon, derived from optical absorption methods (unit: µg/m ), calculated as the ratio of the
measured aerosol light absorption coefficient to an a priori defined Mass Absorption Cross section (MAC)
parameter
3.4
Mass Absorption Cross section
MAC
characteristic value for light absorbing atmospheric aerosol, providing the particle absorption cross
section normalized by the mass of particles causing the observed light absorption (unit m /g) [3]
3.5
refractory Black Carbon
rBC
black carbon, derived from incandescence methods (unit: µg/m ), that address the thermal stability of
the carbonaceous matter [4]
Note 1 to entry: These incandescence methods need specifying means of calibration, conversion factor from
thermal radiation to carbon mass, and the size-cut of rBC particles.
4 Symbols and abbreviations
For the purposes of this document, the abbreviations and acronyms given in EN 16909:2017 and the
following apply.
AMS Automatic measurement system
BC Black carbon
DQO Data quality objectives
EBC Equivalent black carbon
MAC Mass absorption cross section
NDIR non-dispersive infrared detector
OAMS Online aerosol mass spectrometer
PTI Photo-Thermal Interferometry
rBC Refractory black carbon
RM Reference method
5 Potential automatic candidate methods
5.1 Online thermal analyses
Online carbon thermal analysis is based on the analysis of particulate matter collected on a filter located
in the analyser. PM is collected at ambient temperature. The filter is subsequently heated up, and
collected carbonaceous matter evolves from the filter by volatilisation and/or oxidation. Gaseous carbon
compounds can be quantified using various detectors. PM collection and analysis can be performed
automatically in sequence for several days.
5.2 OC and EC determination
Besides the standard method described in EN 16909, many other methods for the determination of the
organic and elemental carbon content of PM samples deposited on filters have been described. The
principle of these methods is similar to that of the standard method (EN 16909), namely that EC is more
refractory than OC.
In particular, OC and EC can be measured automatically and semi-continuously with instruments where
PM collection and OC and EC analyses are performed sequentially. Carbonaceous compounds are oxidized
and detected as CO by e.g. a NDIR. Some instruments can combine the measurement of OC and EC with
measurements of EBC. The thermal protocol described in EN 16909 and light transmittance-based
correction of charring can be applied [5]. The main difference with the standard method (EN 16909) is
that PM sampling is shorter (usually 1 h to 3 h) and the filter is located inside the analyser downstream
of a denuder. Hundreds of sampling/analysis sequences can be performed with a single filter.
Other types of thermal analyses have been used to determine OC and EC in PM samples deposited on
filters. Some methods do not include any optical correction for charring of organic substances. Others
only use oxygen containing carrier gas. Both types of methods distinguish OC from EC from the
temperature at which they evolve. Some of these methods have been implemented in automatic analytical
devices [6].
There is no fundamental reason why OC and EC as determined by automatic analysers would differ from
OC and EC as determined according to EN 16909 as long as the same thermal protocol is used, except for
sampling artefacts. Indeed, different studies of positive and negative sampling artefacts have shown that
the magnitude depends on the use of denuder, sampling face velocity, sampling duration, filter substrate,
pre-firing of filters, ambient temperature and aerosol mixture [7, 8 and 9]. Online thermal analysers can
be equipped with denuders which minimize OC positive sampling artefacts [6].
Pros
The advantage of this method (as compared to other candidate methods) is that it measures OC and EC
mass.
Cons
The disadvantage is that it is semi-continuous only (no sampling during analysis) and time resolution
cannot be less than ½ h.
5.3 TC determination
Online total carbon analysers collect carbonaceous aerosols on a filter which subsequently is heated
rapidly, ≤ 2 min, to a high temperature, ≥ 800°C, under an oxidizing atmosphere. The carbonaceous
aerosol is converted to CO which is quantified by a detector, e.g. NDIR. The TC measurements can be
associated with estimates of OC and EC by parallel, internal or external, optical measurements. Online
thermal TC analysers can be equipped with denuders to minimize OC positive sampling artefacts [10].
Pros
Simplicity (low demand on consumables).
Cons
No
...