【Three-in-one test function】Advanced three-in-one guide pins (TDS, EC, temperature), the tester can detect not only TDS but also EC and temperature in the water. The ppm meter has a range of 0-9990 ppm, and the temperature also supports two reading modes: Celsius and Fahrenheit. 【LCD backlight】The TDS water meter is equipped with low power consumption backlight technology for easy water testing at night or in dark places. It can also be used to distinguish between drinking and non-drinking water. The red backlight (ppm>40) reminds the user that the current water quality is not ideal, indicating that the water is not safe to drink. 【Simple and convenient operation】Just turn on the TDS water meter and stir the water gently, the LCD screen will automatically lock in seconds, the TDS tester will automatically turn off if not used for 2 minutes to save battery power. 【Application】Ideal for tap water quality testing, household water filtration devices, aquariums, swimming pools,