How to check the quality of dissolved oxygen meter

How to check the quality of the dissolved oxygen meter The first step is to check the measurement display unit: set the power switch of the single measurement unit that is not connected to the oxygen electrode to either 'zero adjustment' or 'measurement', and then switch the measurement selection function switch Set the 'temperature' file. The display value should be about 28.0; turn the measurement selection switch to the 'dissolved oxygen' position, set the power switch to the 'measurement' position, and adjust the 'zero adjustment' potentiometer or 'calibration' potentiometer respectively, and the reading display should change. If the above measurement is normal, it can be judged that the measurement display unit is initially qualified, otherwise, there may be a problem with the instrument. The second step, the application judgment of the 'temperature' file when measuring room temperature: insert the oxygen electrode plug into the socket of the instrument, and switch the measurement selection switch to the 'temperature' file. At this time, the room temperature value should be displayed correctly. If the actual measured value deviates greatly , It is necessary to use a multimeter ohm file to detect the oxygen electrode. The third step, the 'dissolved oxygen' level, the judgment and treatment of the oxygen electrode after calibration: after the temperature measurement is normal, switch the measurement selection switch to the 'dissolved oxygen' level, and put the oxygen electrode filled with electrolyte into 5% fresh The self-made sodium sulfite is used for 'zero adjustment' potentiometer zero adjustment; the cleaned electrode is placed in the air, and the 'calibration' potentiometer is adjusted to calibrate the oxygen value corresponding to the temperature. If the reading is too low or too high to reach the required value, you can replace the battery, electrolyte, film, and treat the gold cathode and silver anode according to the product manual. At the same time, the last thing to remind everyone is that you must pay attention to choosing a good dissolved oxygen online monitor. If you encounter a lack of strokes on the dissolved oxygen meter, it is mostly caused by the loosening of the liquid crystal display block pins in the meter. The solution: The front and back covers can be opened, and the liquid crystal display block can be found and reinserted to solve the problem easily.