Fecha de publicación: -- Fuente: WIPO "tomato" A portable system including a detection unit and a controller is disclosed. The detection unit may illuminate a substrate for light spectroscopy, and capture light reflected by the substrate responsive to illuminating the substrate. The controller may obtain inputs from the detection unit, and determine a type of substrate based on the inputs. Responsive to determining the type of substrate, the processor may detect a presence of contaminant on the substrate, and output a notification on a user interface based on the detection. The controller may use one or more machine learning models to detect the presence of contaminant on the substrate.