1 A dual-wavelength photothermal aerosol absorption monitor: design, calibration and performance Luka Drinovec 1,2,3 , Uroš Jagodič 1,2 , Luka Pirker 2,4 , Miha Škarabot 2 , Mario Kurtjak 5 , Kristijan Vidović 6 , Luca Ferrero 7 , Bradley Visser 8 , Jannis Röhrbein 8 , Ernest Weingartner 8 , Daniel M. 5 Kalbermatter 9 , Konstantina Vasilatou 9 , Tobias Bühlmann 9 , Celine Pascale 9 ,Thomas Müller 10 , Alfred Wiedensohler 10 , Griša Močnik 1,2,3 1 Haze Instruments d.o.o., Ljubljana, Slovenia 2 Department of Condensed Matter Physics, Jozef Stefan Institute, Ljubljana, Slovenia 3 Center for Atmospheric Research, University of Nova Gorica, Nova Gorica, Slovenia 10 4 Faculty for mathematics and physics, University of Ljubljana, Ljubljana, Slovenia 5 Advanced Materials Department, Jozef Stefan Institute, Ljubljana, Slovenia 6 Deparment for Analytical Chemistry, National Institute of Chemistry, Ljubljana, Slovenia 7 GEMMA center, University of Milano-Bicocca, Milano, Italy 8 Institute for Sensors and Electronics, University of Applied Sciences Northwestern Switzerland, 15 Windisch, Switzerland 9 Federal Institute of Metrology METAS, Bern, Switzerland 10 Leibniz Institute for Tropospheric Research, Leipzig, Germany Correspondence to: Luka Drinovec (luka.drinovec@haze-instruments.com) 20 https://doi.org/10.5194/amt-2022-21 Preprint. Discussion started: 22 February 2022 c  Author(s) 2022. CC BY 4.0 License.