1) Pour water into a clean glass or cup. 2) Turn the device on and remove the cap. 3) Insert the sensor end (two electrodes) into the water without exceeding the maximum immersion line. 4) Gently stir to remove air bubbles from electrodes. 5) Wait about 5 seconds until the reading stabilizes — the displayed number is the TDS value. 6) Remove the device and shake off excess water. 7) Replace the cap to protect the electrodes. Water Purifier Accessory