Calibration and measurement method of portable dissolved oxygen meter
1. Observe whether the film at the electrode cap is damaged. If there is damage, replace the original electrode cap, add electrolyte to the new electrode cap, replace it on the electrode, and dry the electrode.
2. Weigh 5.00g of anhydrous sodium sulfite solid, dissolve it in distilled water, and prepare a 100mL solution, which is a 5% zero calibration solution.
3. Press the "ON/OFF" button to turn on the power, dry the electrodes, and carefully absorb the moisture on the film.
4. Put the dissolved oxygen electrode into 5% sodium sulfite solution. When the instrument is in the measurement state (the word CONC is displayed in the lower left corner), press the "Mode/Measurement" button, and the instrument will enter the mode selection state.
5. Press the "▲/mg．L-1/%" key or the "▼/Storage" key to select "ZERO" (the lower left corner of the display), press the "OK/Print" key, and the instrument enters the zero oxygen calibration function state. After the reading is stable, press the "OK/Print" key, the instrument will display "0.00mg/L", and the instrument will automatically exit the "ZERO" state after about 5 seconds.
6. Take out the electrode and dry it, put it on the platform, press "▲/mg．L-1/%" key or "▼/storage" key to select "FULL" (the lower left corner of the display), the instrument enters full Oxygen calibration function status, press the "OK/Print" key. After the reading is stable, press the "OK/Print" button, the instrument will display the current dissolved oxygen value, and the instrument will automatically exit the "FULL" state after about 5 seconds.
7. Repeat steps 4.2-4.6 twice until the calibration is stable.
8. If the instrument cannot be reset to zero after repeated calibration or the full-scale dissolved oxygen value is lower than 7mg/L, replace a new electrode and repeat steps 4.2-4.6.
Portable dissolved oxygen meter measurement:
Press "ON/OFF" to turn on the power and directly enter the measurement state (CONC is displayed in the lower left corner). Put the electrode into the solution to be tested, and record after the reading is stable.
