Dissolved oxygen meter electrode cleaning and maintenance methods
When in use, after the electrode of the online dissolved oxygen meter is connected to the meter and powered on, polarization is carried out. In order to balance the chemical system in the electrode, reduce the zero oxygen current and stabilize the electrode. At the beginning, the electrode current is relatively large and decreases exponentially. It usually reaches a stable state after 3 hours. During this period, the displayed data will gradually decrease until stable. Calibration can then be performed.
If there is a continuous power outage for more than 15 minutes, repolarization is required. If the power-off time is not long, the polarization time will be shorter and the system will stabilize faster.
Maintenance of online dissolved oxygen meter electrodes:
1. The dissolved oxygen meter electrode should be cleaned once a week. If there are contaminants on the diaphragm, it will cause measurement errors. Be careful not to damage the diaphragm when cleaning. Rinse the dissolved oxygen meter electrode in clean water. If the dirt cannot be washed away, wipe it carefully with a soft cloth or cotton cloth.
2. The zero point and range of the dissolved oxygen meter electrode should be recalibrated every month.
3. The dissolved oxygen meter electrode is regenerated approximately once a year. When the measurement range cannot be adjusted, the dissolved oxygen electrode needs to be regenerated. Electrode regeneration includes replacing the internal electrolyte, replacing the diaphragm, and cleaning the silver electrode. If oxidation is observed on the silver electrode, polish it with fine sandpaper.
4. If leakage of the dissolved oxygen meter electrode is found during use, the electrolyte must be replaced.
The use of the dissolved oxygen meter after buying it is not only to use it correctly, but also to maintain it. Many customers have problems after buying it before using it. Most of them are caused by technicians accidentally touching the electrode when taking it. The film head is broken, which will cause too much negotiation and turnover between customers and suppliers. Therefore, being regular and careful when using it will avoid a lot of unnecessary trouble.
Dissolved oxygen meter precautions:
1. Calibrate once a day before use, using the water-saturated gas method. Even if the machine is turned off within a day, there is no need to calibrate again;
2. The temperature during calibration and measurement should not differ too much, and should not exceed +-5;
3. If the reading is abnormal, the dissolved oxygen membrane must be replaced (for example, the reading is unstable or does not stabilize from high to low after turning on the machine);
4. When replacing the dissolved oxygen membrane, there should be no bubbles left in the electrolyte, the membrane should not be wrinkled, and the excess membrane should be cut off;
5. The dissolved oxygen membrane must be replaced when the sensor electrolyte dries out;
6. When replacing the dissolved oxygen membrane, use deionized or distilled water to rinse away the old electrolyte, add 2-3 drops of new electrolyte and shake it dry. Ordinary industrial dissolved oxygen meters should be filled with new electrolyte until the liquid surface bulges, and the dissolved oxygen film should be pressed on without leaving any bubbles; half the amount of new electrolyte should be injected into the cover film and tightened;
7. The online dissolved oxygen meter can be used after replacing the cover membrane. After replacing the ordinary membrane, it should be left overnight to allow the membrane to completely restore balance;
8. If the surface of the dissolved oxygen membrane is contaminated, it must be cleaned carefully to avoid damaging the membrane;
9. YSI officially recommends replacing the dissolved oxygen membrane every 2-4 weeks, but if the water quality conditions are good and the maintenance is proper, the dissolved oxygen membrane can even be replaced every six months, provided that each calibration reading is normal;
10. If bubbles continue to appear at the bottom during measurement, the sensor head should be facing up and tied to the cable to prevent bubbles from staying on the surface of the dissolved oxygen film;
11. Dissolved Oxygen Meter Ordinary dissolved oxygen sensors require stirring when measuring. Proper stirring is conducive to obtaining true dissolved oxygen readings. No stirring is required during fast pulse method and microelectrode array (MEA) measurements;
