The following precautions should be taken during use and maintenance:1. Be careful and cautious during use and strictly follow the instructions. Do not loosen the connecting parts of the instrument at , do not drop or collide, and do not allow severe vibration.2. After use, do not put it directly into water for cleaning. Use a clean soft cloth to wipe it. The optical should not be bumped or scratched.3. The instrument should be in a dry place without gases. Calibration: The instrument needs to calibrate the zero point before measurement. Take a few drops of distilled water, put them on the detection prism, turn the zero adjustment screw to adjust the dividing line to the 0% scale position. Then wipe the detection prism clean and perform the test. Some models of instruments require standard liquid instead of distilled water when calibrating. Product Application: Refractometer has the advantages of simple structure, shockproof, easy operation and portability, clear field of vision, low price, etc.Sugar series is used in canned food, juice manufacturing, wine fermentation, beverages, fruits, honey harvesting and other fields.Salt series is used in marine aquaculture, aquarium, physiological saline preparation and other fields.Medical series is used in the detection of serum protein and urine specific . Main technical parameters:Measurement range and minimum scale: Sugar content: 0-40% Minimum scale: 0.2%; Alcohol content: 0-25%; It has temperature compensation function to overcome the data deviation caused by temperature changes and make the data more accurate; The eyepiece has been upgraded, and the lens glass is heavy crown optical glass, not ordinary glass, with higher clarity, reducing the fatigue of the observer. Product name: Handheld wine concentration meter 25-40%; This product adopts domestic advanced manufacturing technology, and its quality and accuracy are other !