Exploring the optical solution by building a low-cost colorimeter

The creation of experimental setups in an educational context, using low-cost, reused, and recycled materials, is a reality of our time. The prominence of activities within the maker culture approach highlights the potential of educational proposals and stimuli in this direction. This work proposes the construction of a low-cost colorimeter prototype, using the light sensor of a smartphone. The work describes the assembly of the prototype, the procedures performed for testing the equipment, and presents the data obtained from the experimental trials. Common household cleaning materials were used for the tests. From the results obtained, it was possible to observe the difference in absorption between the samples used, due to their color, as expected in theory. The cleaning material with the lightest absorption profile was selected for dilution in water, and the result of the relative absorbance versus concentration showed consistency with a correlation factor above 0.93. The prototype demonstrated excellent repeatability in measurements, and this, coupled with its ease of use, indicates that its application could be feasible in a typical classroom setting.

Keywords:
Color; Colorimeter; Absorbance; Arduino; RGB LED