Accurate measurement is based on good calibration, please calibrate the refractometer before using it. Please keep the refractometer dry and clean to make the instrument accurate and durable. Note: Not recommended for wine or other products high in sugar and other ingredients. Simple and fast measuring alcohol refractometer for testing the alcohol volume percentage of brandy, whisky, vodka, etc. Handheld alcohol refractometer with automatic temperature compensation (ATC), no longer have to worry about temperature changes affecting reading accuracy. Refractometers used to measure alcohol volume percent take into account changes in ambient temperature and automatically compensate for them accordingly for accurate and repeatable measurements. Unlimited use: It is a portable optical instrument for bartenders, wine merchants, food manufacturers, etc. The scale range is 0-80%V/V (V/V-alcohol volume percentage), graduation: 1%v/v The alcohol refractometer is made of non-staining, non-corrosive, non-reactive aluminum, easy to carry, resistant to Scratch, durable.