How to calibrate the PH meter?
Generally, the PH meter must be activated when it is not used for a long time. The activation method is to infuse it in 3MOL KCL solution for 24 hours, then rinse it with salt water, and then calibrate with standard solution. The selection of the standard solution is based on you. Usually, the pH value of the water sample is selected.
The following is the calibration method for the PH meter:
1. First check if the electrode is always immersed in the electrode storage solution.
2. Prepare buffer solution with pH 6.86, pH 4.01 and pH 9.18
3, the above two points are satisfied, can be calibrated
4, the mode as the "pH" state
5. Clear the previous calibration data: press the “SETUP” button, the display shows “Clear buffer”, press “ENTER” to confirm
6. Press the “SETUP” button until the display shows “1.68, 4.01, 6.86, 9.18, 12.46” and press “ENTER” to confirm.
7. Carefully remove the electrode from the electrode storage solution, rinse the electrode thoroughly with deionized water, rinse off and blot the surface water with filter paper (be careful! Do not wipe the electrode).
8. The laboratory PH meter does not need to be corrected for a long time. The electrode is immersed in the pH 6.86 buffer solution and stirred evenly. When the value is stable and “S” appears, press the “STANDARDIZE” button and wait for the instrument to automatically calibrate. If the calibration time is too long, press the “ENTER” button to manually calibrate. After the calibration is successful, the value as *calibration point is stored, displaying "6.86" and the electrode slope information "%SlopeXX". XX shows the measured electrode slope value, which is acceptable in the range of 90-105%. If there is only a greater deviation from the theory, an error message (Err) will be displayed, the electrode should be cleaned, and the above steps will be repeated to recalibrate. .
9. Remove the electrode, repeat step 3 to clean the electrode, then immerse the electrode in a pH 4.01 buffer solution and repeat step 8. After the calibration is successful, the value as the second calibration point is stored, displaying (4.016.86) and electrode slope information.
This article is form Allicdata