EN 16976:2024

Ambient air - Determination of the particle number concentration of atmospheric aerosol

This document specifies a standard method for determining the particle number concentration in ambient air in a range up to about 107 cm–3 for averaging times equal to or larger than 1 min. The standard method is based on a Condensation Particle Counter (CPC) operated in the counting mode and an appropriate dilution system for concentrations exceeding the counting mode range. It also defines the performance characteristics and the minimum requirements of the instruments to be used. The lower and upper sizes considered within this document are 10 nm and a few micrometres, respectively. This document gives guidance on sampling, operation, data processing and QA/QC procedures including calibration parameters.

Außenluft - Bestimmung der Partikelanzahlkonzentration des atmosphärischen Aerosols

Dieses Dokument beschreibt ein Standardverfahren zur Bestimmung der Partikelanzahlkonzentration in Außenluft im Bereich bis etwa 107 cm−3 für Mittelungszeiten von mindestens 1 min. Das Standardverfahren basiert auf einem im Zählmodus betriebenen Kondensationspartikelzähler (en: Condensation Particle Counter, CPC) mit geeignetem Verdünnungssystem für Konzentrationen, die den Bereich des Zählmodus überschreiten. Weiterhin werden Leistungskenngrößen und Mindestanforderungen für geeignete Geräte definiert. Die in diesem Dokument betrachteten unteren und oberen Partikelgrößen sind 10 nm bzw. einige Mikrometer. Dieses Dokument beschreibt Probenahme, Betrieb des Geräts, Datenverarbeitung und QA/QC-Maßnahmen, einschließlich der Kalibrierparameter.

Air ambiant - Détermination de la concentration en nombre de particules de l'aérosol atmosphérique

Le présent document spécifie une méthode normalisée de détermination de la concentration en nombre de particules dans l'air ambiant sur une plage allant jusqu'à 107 cm–3 environ, pour des durées de calcul des moyennes supérieures ou égales à 1 min. La méthode normalisée repose sur l'utilisation d'un compteur de particules à noyaux de condensation (CNC) fonctionnant en mode comptage et d'un système de dilution approprié pour les concentrations en dehors de la plage du mode comptage. Ce document spécifie également les caractéristiques de performance et les exigences minimales relatives aux instruments à utiliser. Les tailles de particules minimale et maximale considérées dans le présent document sont, respectivement, de 10 nm et quelques micromètres. Le présent document fournit des recommandations relatives au prélèvement, au fonctionnement, au traitement des données et aux procédures d'assurance qualité et de contrôle qualité, y compris aux paramètres d'étalonnage.

Zunanji zrak - Določevanje številčne koncentracije delcev atmosferskih aerosolov

General Information

• Status: Published
• Publication Date: 25-Jun-2024
• ICS: 13.040.20 - Ambient atmospheres
• Technical Committee: CEN/TC 264 - Air quality
• Drafting Committee: CEN/TC 264/WG 32 - Air quality - Determination of the particle number concentration
• Current Stage: 6055 - CEN Ratification completed (DOR) - Publishing
• Start Date: 19-May-2024
• Due Date: 27-Aug-2024
• Completion Date: 19-May-2024
• Directive: 2008/50/EC - Directive 2008/50/EC of the European Parliament and of the Council of 21 May 2008 on ambient air quality and cleaner air for Europe
• Ref Project: kSIST FprEN 16976:2024 - Ambient air - Determination of the particle number concentration of atmospheric aerosol

Relations

• Revises: CEN/TS 16976:2016 - Ambient air - Determination of the particle number concentration of atmospheric aerosol
• Effective Date: 19-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 16976:2023
01-junij-2023
Zunanji zrak - Določevanje številčne koncentracije delcev atmosferskih aerosolov
Ambient air - Determination of the particle number concentration of atmospheric aerosol
Außenluft - Bestimmung der Partikelanzahlkonzentration des atmosphärischen Aerosols
Air ambiant Détermination de la concentration en nombre de particules de l'aérosol
atmosphérique
Ta slovenski standard je istoveten z: prEN 16976
ICS:
13.040.20 Kakovost okoljskega zraka Ambient atmospheres
oSIST prEN 16976:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 16976:2023
prEN 16976:2023 (E)
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
3.1 Aerosol properties. 6
3.2 Instrument performance . 7
3.3 Flow rates . 7
4 Atmospheric aerosol . 8
5 Description of the method . 8
5.1 Sampling and conditioning . 8
5.1.1 Sampling . 8
5.1.2 Drying . 10
5.1.3 Dilution . 10
5.2 Determination of the number concentration with a CPC . 10
5.2.1 Condensation growth . 10
5.2.2 Optical detection . 12
6 CPC performance criteria and test procedures . 13
6.1 General. 13
6.2 General requirements for the CPC . 13
6.3 Test conditions . 14
6.4 Performance characteristics and criteria . 14
6.5 Test procedures . 15
6.5.1 Calibrated flow rate . 15
6.5.2 Number concentration measurement range . 15
6.5.3 Number concentration detection limit . 15
6.5.4 Calibration factor . 15
6.5.5 Instrument-specific assessment of linearity and slope of response . 16
6.5.6 Detection efficiency curve at low particle size . 16
6.5.7 Upper particle size detection limit . 17
6.5.8 Zero count rate . 17
6.5.9 Response time . 17
6.5.10 Dependence of flow rate on supply voltage. 17
6.5.11 Accuracy of temperature and pressure sensor calibration . 17
6.5.12 Effect of failure of mains voltage . 17
7 Performance criteria and test procedures for the sampling and conditioning system
................................................................................................................................................................... 18
7.1 General requirements . 18
7.2 Performance characteristics and criteria . 18
7.3 Diffusion losses . 18
7.4 Relative humidity. 19
7.5 Dilution . 19
7.5.1 Dilution factor . 19
oSIST prEN 16976:2023
prEN 16976:2023 (E)
7.5.2 General criteria for dilution systems . 19
7.6 Primary sampling flow . 20
8 Measurement procedure . 20
8.1 Measurement planning . 20
8.2 Environmental operating conditions . 20
8.3 Initial installation . 20
8.4 Initial checks on site . 21
8.5 Data processing and reporting . 21
9 Quality control, quality assurance and measurement uncertainty . 21
9.1 General . 21
9.2 Frequency of calibrations, checks and maintenance . 22
9.2.1 General . 22
9.2.2 Maintenance of CPC . 22
9.2.3 Calibration of linearity . 22
9.2.4 CPC zero check . 23
9.2.5 Number concentration check . 23
9.2.6 Check of the actual flow rate . 23
9.2.7 Temperature and pressure sensor calibration . 23
9.2.8 CPC internal diagnostics. 23
9.2.9 Sample system maintenance . 23
9.2.10 Relative humidity sensor . 24
9.2.11 Dilution factor (where applicable) . 24
9.2.12 Leak check . 24
9.3 Measurement uncertainty . 24
9.3.1 General . 24
9.3.2 CPC plateau detection efficiency . 25
9.3.3 CPC detection efficiency drift . 25
9.3.4 Flow determination . 25
9.3.5 Correction to standard temperature and pressure . 25
9.3.6 Diffusion losses in the sampling system . 25
9.3.7 Dilution factor (where applicable) . 26
9.3.8 Calculation of overall uncertainty . 26
Annex A (normative) Determination of diffusion losses in sampling lines . 27
Annex B (informative) Example of the calculation of diffusion losses in a sampling system
................................................................................................................................................................... 29
Annex C (informative) Data reporting . 32
Annex D (informative) Uncertainty calculation (example) . 34
Annex E (informative) Atmospheric aerosols . 36
Annex F (informative) Dilution systems. 39
Annex G (informative) Laminar flow . 46
Annex H (informative) Coincidence correction . 47
Annex I (informative) Results of an experimental comparison of different CPCs . 49
Bibliography . 54

oSIST prEN 16976:2023
prEN 16976:2023 (E)
European foreword
This document (prEN 16976:2023) has been prepared by Technical Committee CEN/TC 264 “Air
quality”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede CEN/TS 16976:2016.
In comparison with the previous edition, the following technical modifications have been made:
— 1: The lower limit of the measured particle size range is set to be 10 nm and thus identical to MPSS
(Mobility Particle Size Spectrometers) measurements (see CEN/TS 17434). In air quality monitoring
networks where MPSS will be used for determining the particle size distribution a CPC may be used
for QA purposes for the MPSS data.
— 3: The parameter “calibration factor” was introduced and defined. The terms and definitions for the
various flow rates were revised and rearranged.
— 5.1.2: Aerosol diffusion dryer based on silica is excluded, because diffusion losses are too high with
this type of dryer.
— 6.2: Coincidence correction shall be applied. No other correction factors shall be applied unless a
correction for the analysed flow rate is necessary.
— 6.3: All tests are carried out only at one temperature (between 20 °C and 30 °C).
— 6.4: Table 1: Criteria for several performance characteristics were changed, the performance
characteristic “calibration factor” was included.
— 6.5: Some of the test procedures have been revised, a test procedure for the calibration factor was
added.
— 7.2: Two dilution factors are necessary: one for reducing the concentration, an additi
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