Abstract
| Original language | English |
|---|---|
| Pages (from-to) | 426-436 |
| Number of pages | 11 |
| Journal | Metrologia |
| Volume | 48 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 2011 |
| MoE publication type | A1 Journal article-refereed |
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Keywords
- aerosols
- particles
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Validating the single charged aerosol reference (SCAR) as a traceable particle number concentration standard for 10 nm to 500 nm aerosol particles. / Högström, Richard (Corresponding Author); Yli-Ojanperä, Jaakko; Rostedt, Antti; Iisakka, Ilkka; Mäkelä, Jyrki M.; Heinonen, Martti; Keskinen, Jorma.
In: Metrologia, Vol. 48, No. 5, 2011, p. 426-436.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - Validating the single charged aerosol reference (SCAR) as a traceable particle number concentration standard for 10 nm to 500 nm aerosol particles
AU - Högström, Richard
AU - Yli-Ojanperä, Jaakko
AU - Rostedt, Antti
AU - Iisakka, Ilkka
AU - Mäkelä, Jyrki M.
AU - Heinonen, Martti
AU - Keskinen, Jorma
PY - 2011
Y1 - 2011
N2 - Measurement of nanometre-sized aerosol particles is based on particle number concentration measurements. The commonly used method for providing traceability for these measurements involves charging and electrical counting of aerosol particles. This method requires that the particles are singly charged or that the average charge is exactly known, neither of which is easy to ensure. In the device called a single charged aerosol reference (SCAR), the fraction of multiply charged particles is minimal due to the novel operating principle of electrical charging and subsequent growth. In this study the SCAR was validated as a primary particle number concentration standard. The average charge of the output aerosol was evaluated for the whole operational particle size range. For this, the effect of the size distribution of the primary nanoaerosol and the output number concentration on the fraction of doubly charged and neutral particles was measured. It was found that the uncertainty caused by assuming singly charged particles is only 0.16%. A full uncertainty analysis was carried out for a condensation particle counter (CPC) calibration. According to the results, the relative expanded uncertainty of calibration was 3.0%. This represents a typical uncertainty level achieved in CPC calibrations performed with SCAR. As a result of this study, SCAR was validated as a particle number concentration standard suitable for traceable calibration of particle counting instruments in the particle size range from 10 nm to 500 nm.
AB - Measurement of nanometre-sized aerosol particles is based on particle number concentration measurements. The commonly used method for providing traceability for these measurements involves charging and electrical counting of aerosol particles. This method requires that the particles are singly charged or that the average charge is exactly known, neither of which is easy to ensure. In the device called a single charged aerosol reference (SCAR), the fraction of multiply charged particles is minimal due to the novel operating principle of electrical charging and subsequent growth. In this study the SCAR was validated as a primary particle number concentration standard. The average charge of the output aerosol was evaluated for the whole operational particle size range. For this, the effect of the size distribution of the primary nanoaerosol and the output number concentration on the fraction of doubly charged and neutral particles was measured. It was found that the uncertainty caused by assuming singly charged particles is only 0.16%. A full uncertainty analysis was carried out for a condensation particle counter (CPC) calibration. According to the results, the relative expanded uncertainty of calibration was 3.0%. This represents a typical uncertainty level achieved in CPC calibrations performed with SCAR. As a result of this study, SCAR was validated as a particle number concentration standard suitable for traceable calibration of particle counting instruments in the particle size range from 10 nm to 500 nm.
KW - aerosols
KW - particles
U2 - 10.1088/0026-1394/48/5/025
DO - 10.1088/0026-1394/48/5/025
M3 - Article
VL - 48
SP - 426
EP - 436
JO - Metrologia
JF - Metrologia
SN - 0026-1394
IS - 5
ER -