@article { ISI:000287796100008,
	title = {Characterization and intercomparison of aerosol absorption photometers: result of two intercomparison workshops},
	journal = {ATMOSPHERIC MEASUREMENT TECHNIQUES},
	volume = {4},
	number = {2},
	year = {2011},
	pages = {245-268},
	abstract = {Absorption photometers for real time application have been available since the 1980s, but the use of filter-based instruments to derive information on aerosol properties (absorption coefficient and black carbon, BC) is still a matter of debate. Several workshops have been conducted to investigate the performance of individual instruments over the intervening years. Two workshops with large sets of aerosol absorption photometers were conducted in 2005 and 2007. The data from these instruments were corrected using existing methods before further analysis. The inter-comparison shows a large variation between the responses to absorbing aerosol particles for different types of instruments. The unit to unit variability between instruments can be up to 30\% for Particle Soot Absorption Photometers (PSAPs) and Aethalometers. Multi Angle Absorption Photometers (MAAPs) showed a variability of less than 5\%. Reasons for the high variability were identified to be variations in sample flow and spot size. It was observed that different flow rates influence system performance with respect to response to absorption and instrumental noise. Measurements with non absorbing particles showed that the current corrections of a cross sensitivity to particle scattering are not sufficient. Remaining cross sensitivities were found to be a function of the total particle load on the filter. The large variation between the response to absorbing aerosol particles for different types of instruments indicates that current correction functions for absorption photometers are not adequate.},
	issn = {1867-1381},
	doi = {10.5194/amt-4-245-2011},
	author = {Mueller, T. and Henzing, J. S. and de Leeuw, G. and Wiedensohler, A. and Alastuey, A. and Angelov, H. and Bizjak, M. and Coen, M. Collaud and Engstrom, J. E. and Gruening, C. and Hillamo, R. and Hoffer, A. and Imre, K. and Ivanow, P. and Jennings, G. and Sun, J. Y. and Kalivitis, N. and Karlsson, H. and Komppula, M. and Laj, P. and Li, S. -M. and Lunder, C. and Marinoni, A. and dos Santos, S. Martins and Moerman, M. and Nowak, A. and Ogren, J. A. and Petzold, A. and Pichon, J. M. and Rodriquez, S. and S. Sharma and Sheridan, P. J. and Teinila, K. and Tuch, T. and Viana, M. and Virkkula, A. and Weingartner, E. and Wilhelm, R. and Wang, Y. Q.}
}
