Abstract
We demonstrate a measurement of aerosol absorption at three wavelengths for particles below 1 μm in diameter using a highly sensitive photoacoustic spectrometer. The acoustic signal is detected with a cantilever microphone, which allows for sensitive detection without the need to apply acoustic resonance to enhance the signal. The lack of resonator makes the instrument compact and well suited for field measurements. A field instrument employing the method was developed and deployed for black carbon monitoring at an air quality measurement station. The method shows excellent sensitivity for in situ aerosol absorption measurement, with detection limits of 0.016, 0.025 and 0.041 Mm-1, for simultaneous measurements at the wavelengths of 445, 520 and 638 nm, respectively, using a 1 h averaging time. The black carbon concentration measured with the new instrument is compared against filter-based photometers operating at the site, showing high correlation.
| Original language | English |
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| Pages (from-to) | 113-124 |
| Journal | Aerosol Research |
| Volume | 3 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 28 Feb 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
This research has been supported by the Research Council of Finland (grant nos. 341271, 342579, 349544, 361835, and 346529), the Jane ja Aatos Erkon Säätiö (Compact and precise sensor for global BC monitoring), and Business Finland (grant no. 6868/31/2022).