Product Measurement Range and Minimum Scale: Brix: 0-40% Minimum Scale: 0.2% Alcohol: 0-25% Instructions: 1) Align the refracting prism with the direction of light and adjust the diopter ring of the eyepiece until the marking line is clear; 2) Adjust the reference: Before measurement, first prepare the standard solution (pure water), the instrument and the liquid to be measured at the same temperature. Open the lid, then take 1-2 drops of standard liquid onto the refracting prism and gently press the lid with your hands to draw a light-dark dividing line. Turn the calibration bolt so that the dividing line between light and dark in the eyepiece's field of view coincides with the reference line (0%); Note: This optical instrument has been adjusted before leaving the factory and can be used directly. 3) Open the cover, wipe the surface of the prism with a soft flannel cloth, take 1-2 drops of the solution to be tested and drop it on the refracting prism, cover the cover and press lightly, read the relative scale of the dividing line between light and dark, which is the measured value The concentration value and the density value of the liquid. 4) After measurement, wipe the attachments on the surface of the prism and the cover with a damp flannel and store it properly after drying. Correction The instrument must be calibrated to zero before measurement. Take a few drops of distilled water, place it on the sensing prism and turn the zero adjustment screw to set the dividing line to the 0% scale position. Then wipe the detection prism for detection. Some instrument models need to set up a standard solution instead of distilled water when calibrating. Ideal for home brewing, wine making, farming, gardening and educational purposes. Note: The data is all measured manually, please allow 1-3cm error, due to the difference in light and display, there will be a certain difference in color, the actual object received shall prevail.