ISO 27891:2015

INTERNATIONAL ISO
STANDARD 27891
First edition
2015-03-01
Aerosol particle number
concentration — Calibration of
condensation particle counters
Densité de particules d’aérosol — Étalonnage de compteurs de
particules d’aérosol à condensation
Reference number
©
ISO 2015
© ISO 2015
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Published in Switzerland
ii © ISO 2015 – All rights reserved

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 5
5 Calibration using reference instruments — General principles . 8
5.1 General principles . 8
5.2 Objectives for the calibration aerosol . 9
5.3 Setup overview . 9
5.4 Components and their requirements .10
5.4.1 Primary aerosol source .10
5.4.2 Charge conditioner .11
5.4.3 DEMC .11
5.4.4 Make-up or bleed air .11
5.4.5 Mixing device, flow splitter and connection tubing .12
5.4.6 Reference instrument: FCAE or CPC .12
5.4.7 Other tools .14
5.5 Differences between FCAE and CPC as a reference instrument .14
6 Calibration using an FCAE as reference instrument .15
6.1 Overview of the setup and calibration procedure .15
6.2 Preparation .18
6.2.1 General preparation .18
6.2.2 Primary aerosol .18
6.2.3 Other equipment .18
6.2.4 DEMC .18
6.2.5 FCAE.19
6.2.6 Test CPC .20
6.2.7 Check of the complete setup .21
6.3 Calibration procedure of detection efficiency .23
6.3.1 General.23
6.3.2 DEMC diameter adjustment .23
6.3.3 Primary aerosol adjustment .23
6.3.4 Splitter bias β measurement .24
6.3.5 Test CPC efficiency measurement .24
6.3.6 Measurement of different particle concentrations .26
6.3.7 Measurement of different sizes .26
6.3.8 Repetition of first measurement point .26
6.3.9 Preparation of the calibration certificate .26
6.4 Measurement uncertainty .26
6.4.1 General.26
6.4.2 Particle size . .27
6.4.3 Detection efficiency .27
6.4.4 Particle number concentration .28
Contents Page
7 Calibration using a CPC as reference instrument .28
7.1 Overview of the setup and calibration procedure .28
7.2 Preparation .31
7.2.1 General preparation .31
7.2.2 Primary aerosol .31
7.2.3 Other equipment .31
7.2.4 DEMC .31
7.2.5 Reference CPC.32
7.2.6 Test CPC .33
7.2.7 Check of the complete setup .33
7.3 Calibration procedure of detection efficiency .35
7.3.1 General.35
7.3.2 DEMC diameter adjustment .35
7.3.3 Primary aerosol adjustment .36
7.3.4 Splitter bias β measurement .36
7.3.5 Test CPC efficiency measurement .37
7.3.6 Measurement of different particle concentrations .38
7.3.7 Measurement of different sizes .38
7.3.8 Repetition of first measurement point .38
7.3.9 Preparation of the calibration certificate .38
7.4 Measurement uncertainty .38
7.4.1 General.38
7.4.2 Particle size . .39
7.4.3 Detection efficiency .39
7.4.4 Particle number concentration .40
8 Reporting of results .40
Annex A (informative) CPC performance characteristics .42
Annex B (informative) Effect of particle surface properties on the CPC detection efficiency .51
Annex C (informative) Example calibration certificates .53
Annex D (normative) Calculation of the CPC detection efficiency .62
Annex E (informative) Traceability diagram .73
Annex F (informative) Diluters .75
Annex G (normative) Evaluation of the concentration bias correction factor between the
inlets of the reference instrument and test CPC .78
Annex H (informative) Extension of calibration range to lower concentrations .83
Annex
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