Ethylene Glycol: -50C to 0C (0%–70%) Propylene Glycol: -50C to 0C (0%–70%) Resolution: 5C, 5% (ATC) Temperature Compensation Range: 10C–30C Field of View Intermediate Scale: (ETHYLENE GLYCOL) Ethylene glycol antifreeze freezing point (PROPYLENE GLYCOL) Propylene glycol type antifreeze freezing point Left Scale: (BATTERY FLUID) Battery liquid specific gravity 1.15–1.20 to be charged 1.20–1.25 power sufficient 1.25–1.30 sufficient power Right Scale: Glass cleaning solution freezing point Principle: The instrument measures the freezing point of antifreeze and glass cleaning agents, as well as the specific gravity of lead-acid battery electrolyte. It includes a temperature compensation device to ensure simple, convenient, and accurate measurements within an ambient temperature range of 10°C to 30°C. The device operates on the principle of the critical angle of total reflection to measure the refractive index of the solution, which is then calibrated to determine the concentration and performance of the liquid. Due to its reliable operation and accuracy, compact size, lightweight design, and ease of use, it is widely used in the automotive industry. Usage Notes: - Do not store the instrument in environments with relative humidity above 85% for extended periods to avoid affecting the optical system. - Avoid liquid or water entering the adjustment knob or eyepiece to prevent damage to internal components. - Avoid dropping or impacting the instrument to maintain measurement accuracy. - After each use, clean the prism and refractive plate with a clean cloth. Package Includes: 1 x Refractometer 1 x Pipette 1 x Instruction Manual 1 x Mini Screwdriver 1 x Cleaning Cloth