Thanks to this refractometer, you can easily check the quality of the grapes and thus better brew your wine! The refractometer is mainly developed to test the sugar content of original grape juice, and then to determine the potential alcohol content of grape wine, fermented grape juice. It cannot be used to measure the alcohol content of wine. Measurement range: Brix (mas sacch): 0-32%, alcohol: 0-25, Resolution: Brix (mas sacch): 0.2%, alcohol: 0.2% Easy to use. Place the 2.3 sample drops on the main prism, close the plate and look out the window at the Brix reading; CALIBRATION: zero calibration with water at 20C, automatic temperature compensation between 10C and 30C (ATC) Sharp precision measurement dividing line (blue-white), easy to read (daylight visible), adjustable eyepiece for focus adjustment Calibration: zero calibration with distilled water at 20C, automatic temperature compensation between 10C and 30 C (ATC). Product Description: Refractometers provide fast and accurate information on the sugar content of grapes and grape musts, berries, fruits pome and stone fruits, as well as unfermented grape juice. After applying sample to prism, special refractometer optics create opposing fields of light and dark. The boundary between the two fields indicates the sugar content of the sample. With the refractometer you can: - Measure the Brix percentage of grapes or other fresh fruit - Determine the progress of harvest maturation - Measure the progress of fermentation - The amount of sugar present as well as the alcohol concentration in the grapes - Let the winegrowers determine whether the fruit is at its peak of maturity and should be harvested.