OPENAIRE OpenAire Sygma DOAJ DIGITAL.CSIC Crossref Copernicus Publications European Union Open Data Portal https://amt.copernicus.org/articles/18/3073/2025/amt-18-3073-2025.pdf https://doi.org/10261/401848 Atmospheric Measurement Techniques Open Access 2025-07-11 2025-02-24 2025-02-24 <?xml version='1.0' encoding='UTF-8'?><article><p>Abstract. A novel reference absorption instrument based on photothermal interferometry – the dual-wavelength photothermal aerosol absorption monitor PTAAM-2λ – and scattering measurements are used to characterize filter photometer artifacts in measurements of absorption coefficients of soot- and dust-dominated aerosol samples within laboratory and ambient campaigns. We provide, for different aerosol types, reference values of the multiple-scattering parameter, quantifying the artifact introduced by the interaction between the light, the particles, and the filter. The Aethalometer AE33 and the Continuous Light Absorption Photometer (CLAP) were characterized during a laboratory campaign where different soot and mineral dust samples were measured. Furthermore, ambient measurements during a campaign in Granada, Spain, were used to characterize the AE33 and MAAP (Multiangle Absorption Photometer), a pseudo-reference absorption instrument. The laboratory campaign showed significant wavelength dependence of the calibration parameter, the multiple-scattering parameter C. The C of the AE33 at 450 and 808 nm was 4.08 and 3.95 and 6.25 and 5.27 for propane soot and diesel soot, respectively. For the CLAP, the C was 5.10 and 4.26 and 6.79 and 5.80 for propane and diesel soot, respectively. For the different mineral dust samples analyzed in the laboratory, the C at 450 nm ranged between 2.74 and 3.03 for the AE33 and between 2.50 and 2.80 for the CLAP. The ambient measurements at Granada showed an overall C of 4.72 at 450 nm and of 3.90 at 808 nm for the AE33. The results for both the AE33 and the CLAP show a dependence with the particle size, with fine particles having the highest C values and with the C being reduced and leveling off for larger particles. Both the laboratory and the ambient measurements of the AE33 showed overlapping results. The cross-sensitivity to scattering was smaller for the CLAP than for the AE33. The values of the cross-sensitivity parameter ms at 450 and 808 nm were 3.0 % and 1.5 % for the AE33 and 2.4 % and 0.9 % for the CLAP. The intercomparison of the MAAP with the PTAAM-2λ during the ambient campaign in Granada showed that the MAAP overestimates the absorption coefficients for 47 % at 637 nm and features a cross-sensitivity to scattering of 2.4 %.</p></article> Make cities and human settlements inclusive, safe, resilient and sustainable Take urgent action to combat climate change and its impacts Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation Earthwork. Foundations TA715-787 Environmental engineering http://metadata.un.org/sdg/13 http://metadata.un.org/sdg/3 TA170-171 Aerosol absorption http://metadata.un.org/sdg/11 http://metadata.un.org/sdg/9 Ensure healthy lives and promote well-being for all at all ages J. Yus-Díez, L. Drinovec, L. Drinovec, L. Alados-Arboledas, G. Titos, E. Bazo, A. Casans, D. Patrón, X. Querol, A. Gonzalez-Romero, C. Perez García-Pando, C. Perez García-Pando, G. Močnik, G. Močnik, 2025-02-24 journalpaper <?xml version='1.0' encoding='UTF-8'?><article><p>Abstract. A novel reference absorption instrument based on photothermal interferometry – the dual-wavelength photothermal aerosol absorption monitor PTAAM-2λ – and scattering measurements are used to characterize filter photometer artifacts in measurements of absorption coefficients of soot- and dust-dominated aerosol samples within laboratory and ambient campaigns. We provide, for different aerosol types, reference values of the multiple-scattering parameter, quantifying the artifact introduced by the interaction between the light, the particles, and the filter. The Aethalometer AE33 and the Continuous Light Absorption Photometer (CLAP) were characterized during a laboratory campaign where different soot and mineral dust samples were measured. Furthermore, ambient measurements during a campaign in Granada, Spain, were used to characterize the AE33 and MAAP (Multiangle Absorption Photometer), a pseudo-reference absorption instrument. The laboratory campaign showed significant wavelength dependence of the calibration parameter, the multiple-scattering parameter C. The C of the AE33 at 450 and 808 nm was 4.08 and 3.95 and 6.25 and 5.27 for propane soot and diesel soot, respectively. For the CLAP, the C was 5.10 and 4.26 and 6.79 and 5.80 for propane and diesel soot, respectively. For the different mineral dust samples analyzed in the laboratory, the C at 450 nm ranged between 2.74 and 3.03 for the AE33 and between 2.50 and 2.80 for the CLAP. The ambient measurements at Granada showed an overall C of 4.72 at 450 nm and of 3.90 at 808 nm for the AE33. The results for both the AE33 and the CLAP show a dependence with the particle size, with fine particles having the highest C values and with the C being reduced and leveling off for larger particles. Both the laboratory and the ambient measurements of the AE33 showed overlapping results. The cross-sensitivity to scattering was smaller for the CLAP than for the AE33. The values of the cross-sensitivity parameter ms at 450 and 808 nm were 3.0 % and 1.5 % for the AE33 and 2.4 % and 0.9 % for the CLAP. The intercomparison of the MAAP with the PTAAM-2λ during the ambient campaign in Granada showed that the MAAP overestimates the absorption coefficients for 47 % at 637 nm and features a cross-sensitivity to scattering of 2.4 %.</p></article> Characterization of filter photometer artifacts in soot and dust measurements – laboratory and ambient experiments using a traceably calibrated aerosol absorption reference 10261/401848 773051