Features: Automatic calibration: The TDS meter has automatic temperature compensation that adjusts for water temperature and water quality, providing a TDS reading almost instantly. Wide use: Suitable for testing TDS value in drinking water, swimming pools, aquariums, spas, or hydroponics. How to use: First remove the pen cover, turn on the ON/OFF switch. Insert the probe into the water, ensuring the water level is below the probe, and stir gently. Wait for the reading to stabilize and read the data. Press the TEMP button to enter temperature measurement mode, then press the switch to return to TDS mode. High-sensitivity alloy probe: Anti-corrosion and anti-rust, provides accurate testing and sensitive response. Power supply: Powered by a button battery, easy to replace. Device is durable and requires recalibration after battery replacement. Note: 1. When the measured value exceeds 999, it will be displayed as X10. 2. The TDS value is affected by water temperature, water flow rate, and water pollution, with an error of 2%-3% of the measurement range. 3. Measuring water temperature