Filter-based measurements of aerosol optical absorption are widely used to determine Black Carbon (BC) concentrations in real time.Measurements at multiple wavelengths (Sandradewi 2008) can identify the contributions from different combustion sources,separating ‘Black Carbon (BC) from ‘Brown Carbon (BrC).These methods sometimes show non-linearity due to ‘loading effects of increasing aerosol deposit on the filter (Gundel,1984; Weingartner,2003; Arnott,2005; Virkkula,2007).These effects are highly variable and cannot be treated by static algorithms,either in post-processing of the data or fixed in the instrument firmware.A dynamical and auto-adaptive approach is required,in order to capture the details and variability of the aerosol optical properties and allow for accurate real-time source apportionment.