describe With this refractometer, you can easily control the quality of your grapes to make your wine better The refractometer is mainly used to detect the sugar content of original grape juice, and then to determine the potential alcohol content of wine and fermented grape juice. It cannot be used to measure the alcohol content of wine. Measuring range: Brix (mas sacch): 0-32%, alcohol: 0-25, resolution: Brix (mas sacch) : 0.2%, alcohol: 0.2% Easy to use. Place 2.3 drops of sample on the main prism, close the plate and view the Brix reading through the window; Calibration: Zero calibration with water at 20C, automatic temperature compensation between 10C and 30C (ATC) Clear and precise measurement separation line (blue -white), easy to read (visible in daylight), adjustable sight glass for focusing Calibration: Zero calibration with distilled water at 20C, automatic temperature compensation between 10C and 30C (ATC). Product Refractometers provide fast and accurate information on the sugar content of grapes and wort, berries, pears and stone fruits, and unfermented wort. Once the sample is applied to the prism, the refractometer's special optics produce fields opposite bright and dark. The border between the two fields represents the sugar content of the sample. With a refractometer, you can: - Measure the Brix percentage of grapes or other fresh fruits is - Determining the ripening progress of crops - Measuring the progress of fermentation - Measuring the sugar content and alcohol concentration in grapes - Allowing winemakers to determine if the fruit is ripe and should be harvested.