Built in high quality chip, high measurement accuracy, sensitive response, fast measurement speed, long-term use. Equipped with high transmittance refraction prism, high precision optical electronic instrument, one thousandth resolution. Support temperature compensation function, automatic calibration, not affected by the environment, automatic elimination of measurement errors. It is equipped with high-definition backlight display, supporting three kinds of data display, clear and intuitive, and more convenient to use. The product needs to be measured after the liquid is mixed evenly. The operation method is simple and practical.