Reasons for Inaccurate Readings of pH Meters
I. Damage to pH Meter or pH Electrode
When measuring standard buffer solutions with a pH meter, if the instrument reading remains unchanged. For instance, when using the FE20K acidity meter to test pH 4.01 and pH 7.0 buffer solutions, the reading stays constant. If the power supply and electrode cables are properly connected, it indicates faults in the main unit or the matching LE438 pH electrode, and maintenance for the device or electrode is required.
II. Malfunction of pH Electrode
As mentioned above, the LE438 electrode may lose activity and need activation treatment. Normal performance can be restored after activation. Refer to relevant guidelines for detailed electrode activation procedures.
III. Inaccurate Readings Caused by Temperature Fluctuations or Sample Changes
The pH value of the same sample may differ when tested at different time intervals. This phenomenon is mainly caused by temperature changes or sample property variations. It is essential to maintain a constant measuring temperature and properly store tested samples.
IV. Reading Deviations Resulting from Improper Calibration
Incorrect selection of calibration buffer solutions, or calibration conducted without temperature compensation at 25℃ will lead to deviations in measurement results.
