Novel method for the continuous mass concentration measurement of ultrafine particles (PM_0.1) with a water-based condensation particle counter (CPC)

Abstract

Measuring the mass concentration (PM_0.1) of ultrafine particles (UFPs; diameter less than 100 nm) continuously, automatically, and accurately poses a considerable challenge because of the typically low PM_0.1 concentration levels and susceptibility to interference from larger particles during the measurement processes. Previous work has shown that PM_0.1 has a strong and stable correlation with the number concentration of particles with diameter above 50 nm (N₅₀). This suggests that the indirect measurement of PM_0.1 might be possible by measuring N₅₀. In this work, the feasibility of using a Condensation Particle Counter (CPC) that measures PM_0.1 by measuring N₅₀ is examined. A water-based CPC was modified to measure N₅₀ (CPC₅₀). The CPC₅₀’s ability to measure PM_0.1 was then evaluated by comparing its measurements with the PM_0.1 measurements of a Scanning Mobility Particle Sizer (SMPS) in a suburban area. PM_0.1 measured by the CPC₅₀ was in good agreement with PM_0.1 measured by the SMPS with a fractional bias (FBIAS) of 4% and a fractional error (FERROR) of 21% for hourly measurements. These findings indicate that a CPC₅₀ could serve as a cheaper alternative to the SMPS, allowing for continuous and real-time measurement of PM_0.1.

Copyright © 2024 American Association for Aerosol Research

Graphical Abstract

Editor:

• Jingkun Jiang

Disclosure statement

The authors report there are no competing interests to declare.

Data availability statement

The data from this work are available upon request from Spyros Pandis ([email protected]).

Additional information

Funding

This work was funded by the project NANOSOMs Grant 11504 of the Greek Hellenic Foundation for Research and Innovation (HFRI).