European (CEN) standardisation work on airborne particles ......European (CEN) standardisation work on airborne particles, and the 2013 EURAMET comparisons for particle number and

European (CEN) standardisation work on airborne particles, and

the 2013 EURAMET comparisons for particle number and charge concentration

Paul Quincey

Particulate Workshop (GAWG), BIPM, Sèvres, 15 April 2015

Outline An update on the position of airborne particle measurements

(1) within international standardisation, and (2) the “SI” traceability framework

These are related; e.g.: ISO 27891:2015 Aerosol particle number concentration -- Calibration of condensation particle counters • The ISO standard refers to the role of NMIs and accredited

laboratories in providing certification for reference CPCs, and aerosol electrometers, which can be used to calibrate CPCs

Are NMIs in a position to take this role?

CEN standardisation CEN TC 264 Air Quality (mostly linked to EU Air Quality Directive)

WG 15 PM10 and PM2.5 – pragmatic rather than traceable EN 12341:2014 Manual (reference) methods prEN 16450 Automatic methods

WG 32 number concentration and size distribution Draft Technical Specifications (TSs) for ambient particle number

concentration and size distribution – refers to ISO 27891 for CPC calibration

WG 34 anions and cations; WG 35 elemental carbon and organic carbon (analysis of material on filters)

Technical Reports 16243 and 16269, currently being upgraded to EN status. Traceability more straightforward (at least for EC+OC)

Also eg CEN TC 137 Assessment of workplace exposure to chemical and biological agents; WG 3 Particulate matter

EN 13205 (many parts) Assessment of sampler performance for measurement of airborne particle concentrations

BIPM Key Comparisons

Establishing NMI capabilities and uncertainties

An NMI sets up facilities and estimates their uncertainties

The NMI takes part in (blind) regional or global Key Comparisons

Calibration and Measurement Capabilities (CMCs) are agreed by international peer-review and included on the Key Comparison Database http://kcdb.bipm.org

Aerosol electrometer comparison EURAMET 1244 compared measurements of airborne charge

concentration (in fC.cm-3) The comparison was based on measurements of a common aerosol

source and was hosted by the Tampere University of Technology (TUT) in Finland on 18-22 March 2013

Particles were mainly from the in-house Single Charge Aerosol Reference (SCAR) generator Approx. 12 nm NaCl particles, singly-charged then grown with di-octyl sebacate to be larger, singly-charged particles

Additional runs with multiply-charged particles using a soot generator

Particle size range: approx. 6 - 200 nm Concentration range: approx 0.15 - 3 fC.cm-3 (equivalent to around

1,000 to 20,000 particles cm-3)

EURAMET 1244

Participant Electrometer NPL (UK) Grimm 5.705 METAS (CH) TSI 3068B MIKES + TUT (FI) self-designed and constructed PTB (D) TSI 3068B

TROPOS (D) TSI 3068B US Army Primary Standards Lab (US) TSI 3068B JRC (EC) Ioner EL-5030 AIST (JP) TSI 3068B

Different designs are expected to disagree at small particle sizes (~

EURAMET 1244

There were 22 comparison runs: Runs 1-8 and 14-16 all used 100 nm sized DOS particles, at nominal concentrations between 1,000 and 18,000 cm-3, three of which were repeated on separate days. Run 18 used larger DOS particles of nominal size 200 nm, at a nominal concentration of 12,000 cm-3. Runs 10-13 used smaller DOS particles of nominal sizes between 20 and 75 nm, at a nominal concentration of 10,000 cm-3. Runs 9, 19 and 20 used small NaCl particles of nominal sizes between 6 and 12 nm, at nominal concentrations between 4,000 to 10,000 cm-3. Runs 21 and 22 used broader size distributions of soot particles, centred on 20 and 30 nm respectively.

EURAMET 1244

100 nm DOS at a range of higher concentrations (Runs 2, 3, 4, 5, 14)

EURAMET 1244

DOS at similar concentrations, with sizes from 20 to 200 nm (Runs 10, 11, 12, 13, 14, 18)

EURAMET 1244

There is more information in NPL Report AS 85 http://www.euramet.org/fileadmin/docs/projects/EURAMET- P1244_METCHEM_Final_Report.pdf and

First comprehensive inter-comparison of aerosol electrometers for particle sizes up to 200 nm and concentration range 1000 cm-3 to 17000 cm-3 R Högström et al Metrologia 51 (2014) 293–303

CPC comparison EURAMET 1282 compared measurements of particle number

concentration (in cm-3) The comparison was based on measurements of a common aerosol

source and was hosted by the TROPOS in Leipzig on 14-18 October 2013

Particles were of 3 types: Silver, sintered (more spherical) Silver, unsintered Soot

Particle size range: approx. 6 - 100 nm Concentration range: approx 100 to 20,000 particles cm-3

EURAMET 1282

Lab CPC model Flow rate (l/min)

Approximate 50% cut-off

size NPL

TROPOS MIKES-TUT

METAS PTB (1) PTB (2)

JRC APSL AIST

TSI 3775 TSI 3772

Airmodus A20 Grimm 5412

TSI 3772 TSI 3790 TSI 3790 TSI 3772 TSI 3772

0.3 1.0 1.0 0.6 1.0 1.0 1.0 1.0 1.0

4 nm 10 nm

~10 nm ~10 nm 10 nm 23 nm 23 nm 10 nm 10 nm

Particle size

Det

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n ef

ficie

ncy

EURAMET 1282

To test: Comparability of CPC calibrations in “plateau” region – only results considered in the “plateau” are presented here; Applicability of calibration for other sizes, materials etc

EURAMET 1282

There were 52 designated runs: Runs 1 - 22 were of sintered Ag particles, of sizes from 6 to 60 nm and concentrations between 100 and 20,000 cm-3. Runs 23 – 32 were of unsintered Ag particles, of sizes 23 or 41 nm and concentrations between 100 and 20,000 cm-3. Runs 33 – 52 were of soot particles, of sizes from 23 to 100 nm and concentrations between 100 and 20,000 cm-3.

EURAMET 1282

60 nm sintered Ag at a range of concentrations (Runs 1 – 5)

EURAMET 1282

26 nm sintered Ag at a range of concentrations (Runs 11 - 15)

EURAMET 1282

41 nm soot at a range of concentrations (Runs 43 – 47)

Summary of comparisons EURAMET 1244 (aerosol electrometer comparison) complete and

written up (NPL AS 85); paper published by Metrologia Broad agreement to ~2% in the range 1 to 3 fC.cm-3 for particle

sizes between 20 and 200 nm

EURAMET 1282 (condensation particle counter comparison) Complete and written up (NPL AS 94) http://www.euramet.org/fileadmin/docs/projects/EURAMET-

P1282_METCHEM_Final_Report.pdf

Agreement is less good than for aerosol electrometers, at around 5%, for the “plateau”. The “plateau” is strongly affected by the particle material.

Thank you

[email protected]

Slide Number 1OutlineCEN standardisationBIPM Key ComparisonsAerosol electrometer comparison EURAMET 1244EURAMET 1244EURAMET 1244EURAMET 1244EURAMET 1244CPC comparisonEURAMET 1282EURAMET 1282EURAMET 1282EURAMET 1282EURAMET 1282EURAMET 1282Summary of comparisonsSlide Number 19