Common Problems of Inaccurate pH Meter Measurements
1. Does the online pH meter transmitter screen display "E.rr"?
Answer: PH exceeds the range. Possible: Indicates that the electrode wiring is disconnected.
2. Does the number of the online pH meter transmitter jump randomly and not match the water quality?
Answer: It may indicate a leakage at the reference connection point. Try wiping the connection terminal with anhydrous alcohol and keeping the humidity at the connection point to meet technical requirements.
3. Is there no control signal output from the online pH transmitter?
Answer: Check if the screen is in normal mode.
4. Do you feel that the measurement value of the online transmitter is inaccurate?
Answer: Remove the electrodes of the online pH meter and clean and calibrate them according to the instructions. If calibration is not possible during the pH meter calibration process, please try replacing the electrodes.
5. Is the electrode reaction slow?
Answer: When the temperature is low, the internal resistance of the electrode increases and the reaction will be slower. When the bubble is covered with dirt and the liquid interface is blocked by dirt, the reaction will slow down. Please try cleaning the electrode.
6. Does the pH of the electrode remain unchanged when placed in any solution?
Answer: The electrode bulb has ruptured and the electrode needs to be replaced. The electrode and instrument wiring have come loose, please check. The electrode cable is internally broken, please replace or send it back for repair.
7. Is the pH value of the same sample different between two measurements?
Answer: Temperature changes or chemical reactions occurring in the sample itself can cause changes in pH value. So, it is advisable to maintain consistent temperature and avoid chemical reactions as much as possible.
8. The same sample is measured on two pH meters at the same time, but the readings are inconsistent?
Answer: Due to the different calibration conditions of the two pH meters (such as calibration done at different times), there are differences in the measured values. So it is necessary to calibrate the pH meter using the same buffer solution at the same time, and then measure it simultaneously.
9. Does the pH meter electrode display unchanged in any sample?
Answer: Because the electrodes are not truly connected to the instrument. The processing method is to first shut down, and then reconnect the electrode and instrument. Because the electrode is damaged, it is necessary to replace it with a new one in a timely manner.
10. Is the measurement unstable and takes a long time?
Answer: Because the electrodes are aging. The response time of the electrode in the buffer solution can be tested. If it is greater than 1 minute, the electrode needs to be activated or replaced with a new electrode. If the response time of the measuring buffer is short but the measured sample is unstable, it indicates that the electrode is not suitable for measuring the tested sample. Please choose the appropriate electrode according to the electrode selection guide.
