10
switch to “Measurement” mode. Calibration is now complete. If
“Mode”
key is pressed instead of the
“Enter”
key, any
changes made will be cancelled and the previous calibration
settings will be retained and will automatically switch to
“Measurement” mode.
b.
2-point calibration
1. Connect the LSDO probe to the unit and turn the unit on.
2. Place the sensor in a solution of zero DO.( A zero DO solution
can be made by dissolving approximately 8 ~ 10 grams of
sodium sulfite (Na2SO3) into 500 mL tap water or DI water.
Mix the solution thoroughly. It may take the solution 60 minutes
to be oxygen-free.).Press
“Mode”
key to select “Dissolved
Oxygen in %” mode.
3. Wait 3 to 5 minutes for the dissolved oxygen and temperature
reading to stabilize, press the
“CAL”
key to enter the
“Calibration” mode. The “CAL” icon appears on the LCD. The
main screen will display “1013 mBar” (factory default value).
The meter is now ready for atmospheric pressure calibration.
4. To change the pressure factor, use the
“Up”
and
“Down”
keys
to adjust the value between 500 and 1125 mBar. Press
“Enter”
key to save the new value and the unit will
automatically go into the next calibration parameter which is
the value of 100% saturation in air. If
“Mode”
key is pressed
instead of the
“Enter”
key, any changes made will be
cancelled and the previous calibration settings will be retained.
5. In this interface, the user can view the calibration value flashing
in the secondary display. Press
"Up"
or
"Down"
key to select
the display to "0.0". Once the value in the main display
stabilizes, press
“
Enter
”
key to save the new value and the
unit will automatically go into the second point calibration. If
“Mode”
key is pressed instead of the
“Enter”
key, any
changes made will be cancelled and the previous calibration
settings will be retained.
6.
Repeat steps 5 to 6 of
“1-point DO% water-saturated air
calibration”
for second point calibration.
C. Dissolved Oxygen Measurements
Press
“Mode”
key to choose the dissolved oxygen in % mode or
dissolved oxygen in mg/L mode. Rinse the LSDO probe with
distilled water and immerse it in the sample to be measured.
