11 common problems with inaccurate pH meter measurements
1. "E.rr" appears on the screen of the online pH meter transmitter?
Answer: The pH is out of range. Possible: Indicates electrode wire disconnected.
2. The numbers on the online pH meter transmitter jump randomly and are inconsistent with the water quality?
Answer: It may indicate leakage at the reference wiring. Try wiping the terminals with absolute alcohol and keep the humidity at the wiring to meet the technical requirements.
3. The online pH transmitter has no control signal output?
Answer: Check whether the screen is in normal mode.
4. Do you feel that the measurement value of the online transmitter is inaccurate?
Answer: Take out the online pH meter electrode, clean and calibrate it according to the instructions. If the pH meter cannot be calibrated during the calibration process, please try to replace the electrode.
5. The electrode response is slow?
Answer: When the temperature is low, the internal resistance of the electrode increases and the reaction will be slower. When the bulb is covered with dirt and the liquid junction is blocked by dirt, the reaction will slow down. Please try cleaning the electrode.
6. Will the pH remain unchanged if the electrode is placed in any solution?
Answer: The electrode bulb has ruptured and the electrode needs to be replaced. The connection between the electrode and the instrument has fallen off, please check. The electrode cable is broken internally, please replace or send it back for repair.
7. For the same sample, the pH values measured twice are different?
Answer: Temperature changes or chemical reactions in the sample itself cause changes in pH value. Therefore, try to keep the temperature consistent and avoid chemical reactions.
8. The same sample was measured on two acidimeters (ph meters) at the same time, and the readings were inconsistent?
Answer: Because the calibration conditions of the two acidimeters (ph meters) are different (such as calibration done at different times), the measured values are different. Therefore, the acidometer (ph meter) must be calibrated with the same buffer at the same time, and then measured at the same time.
9. No matter what kind of sample the pH meter electrode is in, the display remains unchanged?
Answer: Because the electrodes are not actually connected to the meter. The solution is to first shut down the machine and then reconnect the electrode and meter. Because the electrode is broken, it must be replaced with a new one in time.
10. The measurement is unstable and takes a long time?
Answer: Because the electrode is aging. You can test the response time of the electrode in the buffer. If it is longer than 1 minute, the electrode needs to be activated or replaced with a new one. If the response time of the measurement buffer is very short but the measured sample is unstable, it means that the electrode is not suitable for measuring the sample being measured. Please select the appropriate electrode according to the electrode selection guide.
11. The sample temperature is 10°C. At this time, the meter displays the pH value at 10°C or 25°C.
Answer: The acidometer displays the pH value of the solution at the current temperature; if measured at 10°C, the meter displays the value of the solution at 10°C; if a pH of 25°C is required, the solution temperature must be raised/lowered to 25°C. , and then measure. The temperature compensation of the acidometer refers to compensating the influence of temperature on the pH electrode, but it cannot compensate the pH value at any temperature to 25°C.
