Portable high precision PH acidity meter

Instructions for use1. Turn on the Ph meter2. Dissolve each buffer solution in 250 ml distilled water3. Immerse the electrode in a pH 6.86 solution (at 25 temperatures).4. Press and release the "CALdüğ button for 5 seconds- the screen will start flashing 6.86- Wait until the display flashes.Rinse the electrode with distilled water and dry it with filter paper.5. Immerse the electrode in the pH 4.00 solution.Press the “CAL” button for 5 seconds, then immediately press and release again- Reading 4.00 will start to flash- Wait until the display stops flashingThe electrode was rinsed and dried with distilled water as previously described.6. Return the meter to the buffer solution to test the calibration. If it is not correct, please repeat the calibration7. If the approximate pH of the test solution is known to be above 7.0, calibrate the meter using solutions 6.86 and 9.18. To do this, follow the calibration table and the third step is the calibration method at point 9.18.