11 common problems with inaccurate online ph meters
1. online ph meter transmitter screen appears "E.rr"?
A: PH is out of range. Possibly: Indicator electrode wiring is disconnected.
2. online ph meter transmitter figures jumping randomly, and water quality does not match?
A: Possible indication of reference wiring leakage, try to wipe the terminals with anhydrous alcohol, and keep the humidity of the wiring to meet the technical requirements.
3. online PH transmitter no control signal output?
A: Check whether the screen is in normal mode.
4. Feel the online transmitter measurement value is not allowed?
A: Take out the electrode of the online PH meter and clean and calibrate it according to the instruction manual. If you can't calibrate it during the calibration process of the PH meter, please try to replace the electrode.
5. Electrode response is slow?
A: When the temperature is low, the internal resistance of the electrode increases and the response will be slower. When the bulb is covered with dirt, or the liquid junction is blocked by dirt, the response will be slower, please try to clean the electrode.
6. The pH of the electrode does not change when it is placed in any solution?
A: The electrode bulb is broken, need to replace the electrode. The electrode is disconnected from the instrument, please check. The electrode cable is broken inside, please replace it or send it back for repair.
7, the same sample, two measurements of the pH value is not the same?
A: The change of temperature or the chemical reaction of the sample itself has caused the change of pH value. Therefore, we should try to keep the same temperature and avoid chemical reaction.
8, the same sample, measured at the same time in two acidimeter (ph meter), the readings are not consistent?
A: Due to the two acidity meter (ph meter) calibration conditions are not the same (such as different time to do the calibration), resulting in differences in the measured value. So it is necessary to use the same buffer at the same time on the acidity meter (ph meter) calibration, and then measured at the same time.
9, regardless of the ph meter electrode in the kind of sample, the display does not change?
A: Because the electrode is not really connected to the meter. The treatment method is to turn off the machine firstly, and then reconnect the electrode and the meter. Because the electrode is bad, to replace the new electrode in time.
10,Measurement is not stable for a long time?
A: Because the electrode is aging. You can test the response time of the electrode in the buffer, if it is greater than 1 minute, you need to activate the electrode or replace the new electrode. If the response time of the measurement buffer is very short, but the measurement of the sample is not stable, it means that the electrode is not suitable for measuring the sample to be measured, please select a suitable electrode according to the electrode selection guide.
11, the sample temperature of 10 ℃, the meter shows 10 ℃ or 25 ℃ under the pH value
Answer: The pH meter shows the pH value of the solution at the current temperature; if the measurement is made at 10℃, the meter shows the value of the solution at 10℃; if you need to get the pH at 25℃, you have to warm up/cool down the solution temperature to 25℃ and then make the measurement. The temperature compensation of the acid meter refers to compensating the effect of temperature on the pH electrode, but it cannot compensate the pH value at any temperature to 25℃.
