Handheld colorimeter for determination of heavy metal concentrations López Ruiz, Nuria Ariza, María Martínez Olmos, Antonio Vukovic, Jadranka Palma López, Alberto José Capitán Vallvey, Luis Fermín A portable instrument that measures heavy metal concentration from a colorimetric sensor array is presented. The use of eight sensing membranes, placed on a plastic support, allows to obtain the hue component of the HSV colour space of each one in order to determinate the concentration of metals present in a solution. The developed microcontroller-based system captures, in an ambient light environment, an image of the sensor array using an integrated micro-camera and shows the picture in a touch micro-LCD screen which acts as user interface. After image-processing of the regions of interest selected by the user, colour and concentration information are displayed on the screen. 2022-03-11T12:52:23Z 2022-03-11T12:52:23Z 2011 info:eu-repo/semantics/article N López Ruiz et al 2011 J. Phys.: Conf. Ser. 307 012037 http://hdl.handle.net/10481/73333 10.1088/1742-6596/307/1/012037 eng info:eu-repo/semantics/openAccess IOP Publishing