PH818 PH Tester Professional PH Water Quality Tester Portable Pen Type PH Meter Acidometer for Aquarium Acidimeter Measure        Features:  1. Use the data retention function to test the pH and temperature of the solution/water.  2. Pocket size, light weight, easy to carry, switchable backlight and large lcd display for clear reading.  3. Replaceable pH sensor probe The electrode probe can be replaced by a plug-in design, which is convenient and quick.  4. ATC function (automatic temperature compensation), automatic calibration, fully waterproof ip65 design.  5. Suitable for water sources, soilless culture, aquariums, hydroponics, laboratories, spas, swimming pools and other water systems.    Description:  The device is an intelligent precision measuring instrument. It is designed and manufactured with precision components and sensors, with high sensitivity and high precision, stable work at different temperatures, small size, easy to store and carry. It can measure the pH value and solvent temperature of the analyte. It is widely used in pH meters in the fields of industry, electronics and agriculture, medicine, industrial food, etc. It is important to read this manual to obtain correct readings before using this equipment.    How To Operate:  1. Turn on the machine, put the ph818 in pure water, clean it and clean it with a cloth. Press and hold the calibration button, place the machine in the debugged ph4.00 solution, stir for a few seconds, let it sit for a few seconds, until the machine screen appears. "PR5"  2. When the machine number becomes 6.86, remove the machine, wash it with pure water, wipe it with a cloth, put it in the purified ph6.86 solution, stir for a few seconds, let it stand for a few seconds, until the screen of the machine shows prpr5"    Specifications:  PH measurement range:0.00-14.00PH  Basic pH measurement error:±0.05PH  Instrument repeatability:±0.03  Solvent temperature compensation range:0-70°C  Repeatability:±0.01  Test solvent temperature:0-60°C  Power supply:1.5v aaa battery*2 (not included)    Package Included:  Tester*1  Test powder*3  Zipper bag*1  Manual*1    Note:  1. Manual measurement, allow a small error of 0-1cm, thank you.  2. Due to the differences between monitors, the pictures may not reflect the actual color of the item. Please allow a small color difference.