The refractometers are optical devices that are used to calculate the sugar content of a liquid, very useful both in home brewing, or in the care of the wine. They are based on the principle according to which the increase of the density of the substance is proportionally increase the index of refraction. The refractive index is projected on the reading scale of the refractometer, through the lens, from which you can read the measurement result. To measure simply place a drop of liquid on the glass and look through the eyepiece, which allows the calculation of the sugar degrees and then the original gravity of the beer. In the catalog you will find refractometers triple scale, 0-20 or 0-32 Brix Brix well as the most professional electronic models produced by the best companies like Hanna Instruments or Milwaukee.