- Installation of dissolved oxygen meter
The dissolved oxygen meter is generally installed by immersion. It should be noted here that the original installation bracket must be used.
The mounting bracket provided by the manufacturer is made of stainless steel with a plastic chain. The immersion depth of the sensor can be changed by adjusting the length of the chain. The guide tube on the bracket ensures that the sensor is always in a vertical position.
The bracket part is specially designed, it can transmit the fluctuation of the water surface to the immersion tube, which causes slight vibration of the immersion tube, so that an additional cleaning effect is produced on the surface of the probe through the immersion tube.
In order to reduce investment, some users make their own mounting brackets, which often leads to poor sealing between the immersion tube on the bracket and the sensor, and sewage seeps in, so that the connection between the dedicated cable and the sensor is immersed in the sewage for a long time, which may easily cause damage to the sensor; Some even don’t make the mounting bracket, and put the sensor directly into the water. In this way, a larger tension will be formed between the sensor and the cable, and the sensor is more likely to be damaged.
The dissolved oxygen probe should be gently cleaned with water every week. If the membrane head is damaged, it should be replaced in time, and the electrolyte should be replaced in time if it is contaminated.
When the sewage contains H2S, NH3, benzene or phenol, it is harmful to the membrane head. In this case, the membrane head must be replaced frequently.
2. Precautions for dissolved oxygen meter
1. Do a calibration before use every day, using the water-saturated air method, there is no need to calibrate again even if the machine is turned off within a day.
2. The temperature during calibration and measurement should not be too different, preferably not more than +-5℃.
3. If the reading is abnormal, you must change the membrane of the dissolved oxygen meter (for example, the reading is unstable after starting up or it is not stable from high to low).
4. When changing the membrane of the dissolved oxygen meter, there should be no air bubbles 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 is dry.
6. When changing the dissolved oxygen membrane, use deionized water or distilled water to wash off the old electrolyte, and add 2-3 drops of new electrolyte to dry. Ordinary dissolved oxygen sensors should be filled with new electrolyte until the liquid surface swells, and the dissolved oxygen membrane should be pressed on without leaving bubbles; the cover membrane should be filled with half of the new electrolyte and tightened.
7. The cover film can be used after replacement, and the ordinary film should be left overnight after replacement to allow the film to fully restore balance.
8. When the surface of the dissolved oxygen membrane is contaminated, it should be cleaned carefully and the membrane should not be damaged.
9. It is officially recommended to change the dissolved oxygen membrane once 2-4 weeks. However, if the water quality is good and properly maintained, the dissolved oxygen membrane can even be replaced once every six months, provided that the calibration reading is normal each time.
10. If there are continuous bubbles at the bottom during measurement, the dissolved oxygen meter should place the sensor head up and tie it to the cable so that the bubbles cannot stay on the surface of the dissolved oxygen film;
11. Common dissolved oxygen sensors need to be stirred during measurement. Proper stirring is conducive to obtaining true dissolved oxygen readings. The fast pulse method and microelectrode array (MEA) measurement do not require stirring.