" Durable High Quality: It is highly accurate for 0-14 PH measuring range, 0.01 PH resolution, Measures and displays the pH result simultaneously with LCD display, reliable and fast reading. / li> Convenient Operation: Simply remove the protective cap and immerse the pH meter electrode in the solution. Switch on the pH meter using the ON / OFF switch to be measured. Shake gently until the displayed level is stable and read the displayed levels. Pocket Portable: Large LCD display makes it easy to read measurement results. Pocket size for easy transport. the ATC function: Due to the variability of the factors, the temperature of the test objects may have been slightly different, which may result in an inaccurate reading. ATC function can automatically compensate the temperature of test objects, avoid reading inaccuracy. Widely Applicable: Ideal for all home and laboratory pH testing applications including aquariums, swimming pools, aquariums, spas, hydroponics, food, wine and beer making, cosmetics, human urine test and so on. Description use: 1. Switch on the pH meter. 2. Dissolve each buffer solution in 250 ml of distilled water. 3. Soak the electrode in the PH 6.86 solution (at a temperature of 25) 4. Press the "CAL" button for 5 seconds and release. - The screen starts flashing 6.86 - The screen stops flashing. Rinse the electrode with distilled water and dry with filter paper. 5. Soak the electrode in the PH 4.00 solution, - Press the "CAL" button for 5 seconds, then press and immediately release the second time. - Playback will start flashing 4. - The screen must stop flashing, rinse and dry the electrode with distilled water as before. 6. Return the tool to the buffer solution to test the calibration. If an error occurs, repeat the calibration. 7. If you know that the approximate pH of the test solution is greater than 7.0, calibrate the tool using solution 6.86 and 9.18. "