Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor
An evaluation of the Cavity Attenuated Phase Shift particle light extinction monitor (CAPS PM<sub>ex</sub>) using a combination of a 3-wavelength Integrating Nephelometer (NEPH) and a 3-wavelength filter-based Particle Soot Absorption Photometer (PSAP) was carried out using both laborato...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2013-05-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | http://www.atmos-meas-tech.net/6/1141/2013/amt-6-1141-2013.pdf |
| _version_ | 1811206866663899136 |
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| author | A. Petzold T. Onasch P. Kebabian A. Freedman |
| author_facet | A. Petzold T. Onasch P. Kebabian A. Freedman |
| author_sort | A. Petzold |
| collection | DOAJ |
| description | An evaluation of the Cavity Attenuated Phase Shift particle light extinction monitor (CAPS PM<sub>ex</sub>) using a combination of a 3-wavelength Integrating Nephelometer (NEPH) and a 3-wavelength filter-based Particle Soot Absorption Photometer (PSAP) was carried out using both laboratory-generated test particles and ambient aerosols. An accurate determination of a fixed pathlength correction for the CAPS PM<sub>ex</sub> was made by comparing extinction measurements using monodisperse PSL spheres in combination with Mie scattering calculations to account for the presence of PSL conglomerates. These studies yielded a linear instrument response over the investigated dynamical range from 20 to 450 Mm<sup>−1</sup> (10<sup>−6</sup> m<sup>−1</sup>) with a linear correlation coefficient of <i>R</i><sup>2</sup> > 0.98. The adjustment factor was determined to be 1.05 times that previously reported. Correlating CAPS extinction to extinction measured by the NEPH + PSAP combination using laboratory-generated polydisperse mixtures of purely scattering ammonium sulfate and highly absorbing black carbon provided a linear regression line with slope <i>m</i> = 1.00 (<i>R</i><sup>2</sup> = 0.994) for single-scattering albedo values (λ = 630 nm) ranging from 0.35 (black carbon) to 1.00 (ammonium sulfate). For ambient aerosol, light extinction measured by CAPS was highly correlated (<i>R</i><sup>2</sup> = 0.995) to extinction measured by the NEPH + PSAP combination with slope <i>m</i> = 0.95. |
| first_indexed | 2024-04-12T03:54:04Z |
| format | Article |
| id | doaj.art-8b6013480f524f728472763649dbfec3 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-12T03:54:04Z |
| publishDate | 2013-05-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-8b6013480f524f728472763649dbfec32022-12-22T03:48:53ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482013-05-01651141115110.5194/amt-6-1141-2013Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitorA. PetzoldT. OnaschP. KebabianA. FreedmanAn evaluation of the Cavity Attenuated Phase Shift particle light extinction monitor (CAPS PM<sub>ex</sub>) using a combination of a 3-wavelength Integrating Nephelometer (NEPH) and a 3-wavelength filter-based Particle Soot Absorption Photometer (PSAP) was carried out using both laboratory-generated test particles and ambient aerosols. An accurate determination of a fixed pathlength correction for the CAPS PM<sub>ex</sub> was made by comparing extinction measurements using monodisperse PSL spheres in combination with Mie scattering calculations to account for the presence of PSL conglomerates. These studies yielded a linear instrument response over the investigated dynamical range from 20 to 450 Mm<sup>−1</sup> (10<sup>−6</sup> m<sup>−1</sup>) with a linear correlation coefficient of <i>R</i><sup>2</sup> > 0.98. The adjustment factor was determined to be 1.05 times that previously reported. Correlating CAPS extinction to extinction measured by the NEPH + PSAP combination using laboratory-generated polydisperse mixtures of purely scattering ammonium sulfate and highly absorbing black carbon provided a linear regression line with slope <i>m</i> = 1.00 (<i>R</i><sup>2</sup> = 0.994) for single-scattering albedo values (λ = 630 nm) ranging from 0.35 (black carbon) to 1.00 (ammonium sulfate). For ambient aerosol, light extinction measured by CAPS was highly correlated (<i>R</i><sup>2</sup> = 0.995) to extinction measured by the NEPH + PSAP combination with slope <i>m</i> = 0.95.http://www.atmos-meas-tech.net/6/1141/2013/amt-6-1141-2013.pdf |
| spellingShingle | A. Petzold T. Onasch P. Kebabian A. Freedman Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor Atmospheric Measurement Techniques |
| title | Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor |
| title_full | Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor |
| title_fullStr | Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor |
| title_full_unstemmed | Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor |
| title_short | Intercomparison of a Cavity Attenuated Phase Shift-based extinction monitor (CAPS PMex) with an integrating nephelometer and a filter-based absorption monitor |
| title_sort | intercomparison of a cavity attenuated phase shift based extinction monitor caps pmex with an integrating nephelometer and a filter based absorption monitor |
| url | http://www.atmos-meas-tech.net/6/1141/2013/amt-6-1141-2013.pdf |
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