General Description This 4-in-1 refractometer is designed to measure the concentration of ethylene glycol and propylene glycol, as well as the freezing point of various liquids such as coolant, washer fluid, AdBlue, and batteries. It is ideal for use in cars, solar installations, heat pumps, and other heating or water systems. Technical Specifications Measurement Range: Ethanediol (ethylene glycol): 0 to -50 °C Propanediol (propylene glycol): 0 to -50 °C Windshield washer fluid (ethanol + water): 0 °C to -40 °C Propanediol + water (SRF1): 0 °C to -40 °C AdBlue: urea concentration 30% - 35% Acid battery: 1.10 to 1.40 kg/L Calibration: Zero calibration with distilled water at 20 °C Automatic Temperature Compensation (ATC): between 10 °C and 30 °C Magnification: 4-8 times with progressive manual focusing Usage This refractometer is easy to use and comes with a manual in French and three other languages. It is designed to suit all users, including those with visual impairments, without requiring glasses to read the measured data.