The refractometer is used to measure the sugar content in the raw grape juice, and then the alcohol content in the wine (made from grape juice) can be known from the scale, and the grape juice can be fermented (by volume) by measuring the alcohol content. Range-Brix: 0-40%, Alcohol: 0-25% Easy to use-Put 2, 3 drops of the sample on the main prism, close the plate and read the Brix value through the observation window. Calibration-Use 20 C water for zero calibration, automatic temperature compensation 0-30C (ATC) Packaging-refractometer, hard plastic box, mini screwdriver, 1* pipette, instruction manual. The refractometer mainly measures the sugar content of grape juice, thereby predicting the alcohol content of the wine produced. Because the alcohol content of wine is positively correlated with the sugar content of grape juice, of course, if you use it as a sugar meter, it is designed according to the principle of different refractive indexes of liquids of different concentrations. It has fast speed, high accuracy, and weight. Lightweight, small size and other advantages. How to use: Open the lid and check the prism carefully with a soft cloth. Take a few drops of the solution to be tested and place them on the detection prism. Then gently close the lid to avoid air bubbles, and apply the solution to the entire prism surface. Aim the light entrance plate of the instrument at the light source or a bright place, observe the field of view through the eyepiece, and turn the eyepiece adjustment hand wheel to make the blue and white boundary of the field of view clear. The scale of the dividing line is the concentration of the solution. Calibration and temperature calibration: the instrument needs to be calibrated to zero before measurement. Put a few drops of distilled water on the detection prism. Turn the zero adjustment screw to adjust the scale to 0% of the scale. Then wipe and test the detection prism. Another method (only for determining the sugar content) is to use a temperature correction table, and then add (or subtract) the temperature correction value to the value read at the ambient temperature to get an accurate value. (The manual includes a temperature correction table for sugar readings.) Packaging: 1 x refractometer, 1 x hard plastic box, 1 x mini screwdriver, 1 x pipette, 1 x manual calibration and temperature .