Abstract: the sweat test (ST) is essential in the diagnosis of cystic fibrosis (CF) whose protocol provides for the measurement of chloride in sweat. One of the techniques used to measure sweat is colorimetry. In this technique, a visible light spectrophotometer measures the absorbance of sweat samples added to a specific reagent. The amount of light absorbed is directly related to the concentration of chlorides in the sweat. This article proposes the development and testing of a low-cost sensor for the quantification of chlorides in sweat. A sensor was developed using the rapid prototyping (3D) technique dedicated to absorbance measurement for colorimetric technique. An experimental work was carried out using two groups of solutions, the first group being prepared with dyes and the second group prepared with a sweat-like solution added to a commercial reagent widely used for the purposes of dosing chlorides in sweat in order to verify the applicability of the sensor. The sensor responded appropriately and presented linearity (R2?=?0.9954) with statistical equality (p?>?0.05) in six tests. The comparison between the prototype and the reference equipment showed statistical equality (p?>?0.05). Based on the results, we believe that the sensor can be used to measure chloride in sweat Ver menos