A single-beam photothermal interferometer for in situ measurements of aerosol light absorptionBradley Visser
, Jannis Röhrbein
, Peter Steigmeier
, Luka Drinovec
, Griša Močnik
, Ernest Weingartner
, 2020, original scientific article
Abstract: We have developed a novel single-beam photothermal interferometer and present here its application for the measurement of aerosol light absorption. The use of only a single laser beam allows for a compact optical set-up and significantly easier alignment compared to standard dual-beam photothermal interferometers, making it ideal for field measurements. Due to a unique configuration of the reference interferometer arm, light absorption by aerosols can be determined directly – even in the presence of light-absorbing gases. The instrument can be calibrated directly with light-absorbing gases, such as NO2, and can be used to calibrate other light absorption instruments. The detection limits (1σ) for absorption for 10 and 60 s averaging times were determined to be 14.6 and 7.4 Mm−1, respectively, which for a mass absorption cross section of 10 m2 g−1 leads to equivalent black carbon concentration detection limits of 1460 and 740 ng m−3, respectively. The detection limit could be reduced further by improvements to the isolation of the instrument and the signal detection and processing schemes employed.
Found in: ključnih besedah
Summary of found: ...aerosol, aerosol absorption, black carbon, photo-thermal interferometer, climate change...
Keywords: aerosol, aerosol absorption, black carbon, photo-thermal interferometer, climate change
Published: 29.12.2020; Views: 1308; Downloads: 35
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