[New function TDS]: TDS: 0-9990 NT, accuracy: +/-2%. The TDS meter can measure TDS, EC and liquid temperature in Fahrenheit or Celsius. TDS is used to test the quality of the water purifier and has a backlight function for easy reading. [0.01 high- hand-held PH meter]: PH measurement range: 0-14PH, accuracy: +/-0.01 PH. The pH meter can tell you the acid base value. PH has automatic temperature compensation function. [Easy to use and calibrate]: Both the digital TDS and the PH meter have an automatic shutdown function, which automatically shut down after 5 minutes of non-use to save battery life. The TDS&PH meter can be turned on and used by pressing "ON/OFF", and it can be turned off by pressing "ON/OFF". Press the "CAL" button to immerse the electrode in the liquid for calibration. The TDS meter is automatically calibrated after it is turned off. [Wide application]: PH and TDS thermometers can test the hardness and pH value of water, which can effectively the quality and health of water. They are suitable for many occasions, such as drinking water, aquariums, hydroponics, spas, swimming pools and other water systems., Weight: 0.35384193051 pounds, Manufacturer: Aisuoka