Refractometers are highly precise optical instruments whose function is to determine the percentage of soluble solids in a liquid solution, using the principle of total refraction of light (originated by the type and concentration of the substances dissolved in a liquid solution, for example, sugar), which takes place in the boundary layer between the prism and the sample. Therefore, it can be said that the refractometer measures the density of liquids, the denser a liquid the greater the refraction, the more the sugar content, the higher the refraction index. The portable refractometers are simple, resistant and reliable, allowing us to make measurements in the laboratories or outside, with exact measurements of temperatures, refractive index, density pH and color with a small sample, setting aside reliable results, increasing safety and avoiding errors, in addition to reducing costs and improving the operational safety of the laboratory.