Frequently asked questions and answers for pH meters
There are two situations that can cause the above problems:
(1) Temperature changes may cause differences in the measured pH value. Please keep the measured temperature unchanged.
(2) The sample itself has undergone a chemical reaction, resulting in a difference in the measured pH value. Please measure the sample as soon as possible and pay attention to the storage conditions of the sample.
What is the reason why the pH displayed as 7.00 after calibration with pH 6.86 buffer solution?
The wrong buffer group was selected, and the correct buffer group needs to be reset (see instrument operation manual). Or during calibration
The buffer temperature is not at 25 ℃.
Why can't the new electrode be calibrated or have unstable values?
This may be because there are bubbles in the electrode sensitive membrane or gel, which leads to abnormal potential changes, so it is necessary to remove the bubbles
Swipe the electrode downwards (like a thermometer) to drive away the bubbles. If not in use, the electrode can be placed vertically.
If the electrode sensitive film is left dry for too long, it needs to be activated in 0.1mol/L dilute hydrochloric acid.
Why is the electrode measurement value unstable?
There may be two situations that can cause the above issues:
(1) The electrode selection is not appropriate.
If the response time of the measuring buffer is short but the measuring sample is unstable, it indicates that the electrode is not suitable for measuring the tested sample (electrode selection)
