AZ-400H 2 in 1 Multifunctional Waterproof Professional Water Quality Monitor Tester Portable Pen Type Hydrogen-Rich Water Detector for Drinking WaterFeature:IP67 WaterproofHD Backlit DisplayEasy to CarrySpecification:Shell Material: ABSiration: 3 x LR44 Button Batteries (Not Included)Size: 183x3 7mm/7.2x1.46inApplication: Suitable for water quality monitoring, such as farmland irrigation, aquaculture, laboratories, etc. Working Guide: Before use, pull out the electrode protective cover under the test pen, just pull it out directly, do not rotate!1. Determination of Hydrogen ContentRemove the hydrogen-rich test pen from the box and press the ON/OFF button to turn it on. After the value displayed on the screen is "0", put the unit into the water to be tested for testing2. Conversion ppb/ppm1. The default unit of measurement for the instrument is ppb2. In the power-on state, click the "FUN" button to switch the measurement mode between ppb and ppm. (1ppm = 1000ppb)3. Automatic Temperature Compensation (ATC)There on a turnkey basis is the ATC symbol at the bottom left corner of the display, which means the instrument is in automatic temperature compensation.4. Lock FunctionWhen the test pen is working normally, pressing the "HOLD" key will lock the current data on the display screen and the HOLD symbol will appear on the display screen. Press the "HOLD" button again to release the lock mode and the HOLD symbol will disappear.5. Overrange DisplayWhen the hydrogen-rich measurement value is greater than 2400 ppb (2.400ppm), the display area will show the overrange symbol: "- - -". When the temperature is below 0°C or above 50°C, the temperature display area will be displayed: "L" symbol and "H" symbol.6. Low voltage promptWhen the display is dimmed and the battery symbol appears at the top of the display, it means that the battery voltage is insufficient, replace the new battery as soon as possible, and do not mix old and new batteries. Maintenance: Even under normal use, attachments or other dirt will appear on the electrode sensor, which will affect the contact area between the electrode sensor and the water, thereby affecting the sensitivity and accuracy of the test. Before use, use a cotton swab dipped in a small toothpaste to clean it, then wipe the sensor pad with a paper towel dipped in water. Keep the electrode surface clean and bright before testing. After each use, wash the electrode to be cleaned with water, dry the water on the electrode with absorbent paper, cover the electrode protective cover, and place it in a cool and ventilated place. Note:Due to the different monitor and light effect, the actual color of the item may be slightly different from the color showed on the pictures. Please allow 1-2cm measurement deviation due to manual measurement. 1 X Water Quality Detector 1.