Cantilever-enhanced photoacoustic measurement of light-absorbing aerosols
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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Date
2021
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Language
en
Pages
10
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Aerosol Science and Technology
Abstract
Photoacoustic detection is a sensitive method for measurement of light-absorbing particles directly in the aerosol phase. In this article, we demonstrate a new sensitive technique for photoacoustic aerosol absorption measurements using a cantilever microphone for the detection of the photoacoustic signal. Compared to conventional diaphragm microphones, a cantilever offers increased sensitivity by up to two orders of magnitude. The measurement setup uses a photoacoustic cell from Gasera PA201 gas measurement system, which we have adapted for aerosol measurements. Here we reached a noise level of 0.013 Mm−1 (one standard deviation) with a sampling time of 20 s, using a simple single-pass design without a need for a resonant acoustic cell. The sampling time includes 10 s signal averaging time and 10 s sample exchange, since the photoacoustic cell is designed for closed cell operation. We demonstrate the method in measurements of size-selected nigrosin particles and ambient black carbon. Due to the exceptional sensitivity, the technique shows great potential for applications where low detection limits are required, for example size-selected absorption measurements and black carbon detection in ultra clean environments.Description
Publisher Copyright: © 2021 The Author(s). Published with license by Taylor and Francis Group, LLC.
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Hans Moosmüller
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Citation
Karhu, J, Kuula, J, Virkkula, A, Timonen, H, Vainio, M & Hieta, T 2021, ' Cantilever-enhanced photoacoustic measurement of light-absorbing aerosols ', Aerosol Science and Technology, vol. 56, no. 1, pp. 92-100 . https://doi.org/10.1080/02786826.2021.1998338