Unique Temperature Compensation Function: Can automatically convert the TDS value at 25 water temperature TDS Value: Represents the total content of water-soluble substances, for example: calcium, magnesium ions and some trace elements etc. Large LCD display, waterproof design, easy to watch TDS value(can not test PH or certain value of dissolved substance in solution ) More Accurate and Fast: Titanium alloy test probe, the measurement value is not affected by the magnetic field in the water, the measurement value is more accurate Energy Saving and Durable: Long using time without frequent battery replacement, normal use for two years(1.5V*2 button battery) Feature : Low power consumption and automatically shut down. Used in swimming pool, waterworks laboratory, disease control center, aquaculture, hospital Titanium alloy test probe, the measurement value is not affected by the magnetic field in the water Unique Temperature Compensation function can automatically convert the TDS value to a water temperature of 25 [Factors Affecting TDS Testing] Water temperature: The TDS pen cannot be used to measure the high temperature water (eg: hot water) Water flow: TDS pens cannot be used to measure large bodies of water [Product Application Range] The quality of tap water, purified water and mineral water is tested to meet the country's drinking water standards : less than 300PPM of tap water, 50ppm of pure water (national standards) and 100-200PPM of mineral water. [TDS Test] Please remove the electrode sleeve Press the button of on/off, then put the electrode into the measured solution (Please do not exceed the immersion line-See photo) Wait until the value is stable(2-6sds), press the hold button and read the TDS figure displayed on the LCD screen When the measurement is finished, press the on/off button to close TDS tester, wipe the electrode, then cover the electrode protection sleeve Specification : Net weight: 28g Error range: 2% Battery: 1.5V*2 (button battery ) Battery life: 14.2 * 2.3 * 1.3(cm) Measurement range: 1-9990 PPM(999PPM or more automatic *10) Warning: Avoid shock, weight and falling Avoid heat, exposure to direct light