Dissolved oxygen electrodes are widely used in water quality monitoring and other fields, but some faults often occur during use, which affect the accuracy of measurement results. It is necessary to understand these common faults and maintenance methods.

　　1、 Common faults

　　1. Inaccurate reading:

① Unstable temperature can cause measurement results to deviate, as electrode measurements are affected by temperature and require the use of temperature stabilizers or correction of temperature coefficients.

② In high salinity environments, measurement results may also be affected and may require recalibration with low salinity standard solutions.

③ The attachment of pollutants in water to the electrode, or the presence of bubbles or foreign objects between the electrode and the solution, can lead to inaccurate readings or even "drift phenomenon".

④ After electrode aging, the response speed slows down and the readings are inaccurate.

　　2. Unstable conductivity:

There are bubbles or foreign objects between the electrode and the solution, which can cause unstable conductivity and inaccurate or even "drift" electrode readings. This situation may require cleaning the electrode or replacing it with a new one.

　　3. Abnormal measurement values:

Surface contamination on the electrode cap, damage to the thin film, expiration of the working life of the electrode cap, contamination on the inside of the electrode cap and the electrode tip with the fixing ring not tightened, incorrect temperature display (insufficient or damaged immersion depth of the temperature probe), failure to cover the electrode cap, failure to recognize the electrode cap, damage to the electrode cap, etc., may all cause abnormal measurement values, such as incorrect information such as test values being too high or too low.

　　2、 Repair method

　　Regarding pollutants and bubbles:

For situations where pollutants are attached to the electrode, if it is a regular electrode, rinse it with clean water and do not wipe the electrode membrane cap with your hands or other hard objects; If it is an optical dissolved oxygen electrode, check the appearance before use and connect it with ArcAir or a flat plate to check the performance indicators. If the indicators are low, replace the photo oxygen film cap. When installing, pay attention to the specifications and do not add electrolyte to the film cap. If there is internal contamination, wipe the glass window with lens paper.

　　2. Electrode aging and regeneration:

When the electrode ages, it can generally be regenerated after about 1 year, including replacing the internal electrolyte, replacing the membrane, cleaning the silver electrode. If the silver electrode has oxidation, it can be polished with fine sandpaper.

　　3. Other situations:

If there are temperature related issues, ensure that the temperature probe is deeply immersed and send it back for repair if damaged; When the electrode cap is not installed or recognized, install or replace it accordingly; Replace the electrode cap if it is damaged. At the same time, it is necessary to regularly clean the electrodes (once every 1-2 weeks), calibrate the zero point and range (once every 2-3 months), regenerate the electrodes (once every year or so), and replace the electrolyte when electrode leakage is found.