1. Use the water saturated gas method to calibrate once a day before use, and 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 it is advisable not to exceed+/-5 ℃;

3. If the reading is abnormal, it is necessary to replace the dissolved oxygen membrane (such as if the reading is unstable or not stable from high to low after startup);

4. When replacing the dissolved oxygen membrane, there should be no bubbles left in the electrolyte, the membrane should not be wrinkled, and any excess membrane should be removed thoroughly;

5. When the sensor electrolyte is dry, it is necessary to replace the dissolved oxygen membrane;

6. When replacing the dissolved oxygen membrane, rinse off the old electrolyte with deionized water or distilled water, and add 2-3 drops of new electrolyte to shake dry. A regular dissolved oxygen sensor should be filled with a new electrolytic liquid surface, bulged, and pressed with a dissolved oxygen film without leaving any bubbles; Inject half of the new electrolyte into the cover film and tighten it;

7. After replacing the cover film, it can be used. After replacing the ordinary film, leave it overnight to fully restore balance;

8. The surface of the dissolved oxygen membrane should be carefully cleaned to prevent damage to the membrane;

9. It is recommended to replace the dissolved oxygen membrane every 2-4 weeks, but with good water quality and proper maintenance, it can even be replaced every six months, provided that each calibration reading is normal;

10. When measuring, if bubbles continuously appear at the bottom, the sensor head should be facing upwards and tied to the cable, and the bubbles should not stay on the surface of the dissolved oxygen film;

11. Ordinary dissolved oxygen sensors require stirring for measurement, and appropriate stirring is beneficial for obtaining accurate dissolved oxygen readings. Fast pulse method and microelectrode array (MEA) measurement do not require stirring.