7
SALINITY CORRECTION
BAROMETRIC PRESSURE SETTING:
C-2) Zero Dissolved Oxygen Calibration:
(Laboratory calibration with Na
2
SO
3
powder)
NOTE:
Generally need to do zero oxygen calibration in the situation of replacing
new electrode, replacing membrane cap, and long time without using. To do zero dissolved
oxygen calibration by the following steps:
1) Connect the electrode to the meter.
2) Use the beaker by dissolving approximately 10 grams of Na
2
SO
3
in 500 ml of
distilled water.
3) Place the electrode in the Na
2
SO
3
solution and wait for the reading to stabilize,
press and hold
MODE+CAL
buttons to enter calibration mode, press
MODE+ADJ+UNIT
buttons
again to enter “
DO %0.0
” mode, then press and hold
SET
button to save and screen shows “
SA”
to complete
calibration.
Press and hold
MODE+CAL
buttons, screen shows
“ESC”
momentarily and return to normal measurement
mode
C-3) 100% Air-Saturated Water Calibration:
(Laboratory calibration with stirrer)
1) Connect the electrode to the meter.
2) Pour 100ml deionized water into a 150mL beaker. Use an air bubbler or some
type of aerator to bubble air through the water while stirring for
20
minutes until
the water becomes completely saturated with air.
3) Place the electrode in the air-saturated water and wait for the reading to stabilize,
press and hold
MODE+CAL
buttons to enter calibration mode, screen shows “
DO %100
”, then press and hold
SET
button to save and screen shows “
SA”
to complete calibration. Press and hold
MODE+CAL
buttons, screen shows
“ESC”
momentarily and return to normal measurement mode.
Due to the solution contains significant concentration of salinity affects the read out values of DO.
Thus, to correct salinity value is required in order to get the accurate DO reading.
(Refer to
page 8
,
CHART 1
. for reference). Use a salinity meter to get the salt concentration reading.
1) To enter the known salinity value by long press
SET
button and the screen shows “
SAL
”.
HOLD:
↑to increase
ADJ:
↓to decrease
SET:
← to left digit
CAL:
→ to right
digit
Adjustable range is 0 to 45.2 ppt.
2) After setting completed, press and hold
MODE
button to save setting, screen shows “
SA
”
to complete setting. To escape the setting by press and hold
SET
button, screen shows
“
ESC
” and return to normal measurement mode.
If you are performing measurements at an altitude different from sea level 760 mmhg
(default value). It is important to enter correct barometric pressure as barometric
pressure affects DO values. (Refer to
page 9
,
CHART 2
. for reference)
1) To enter the known pressure value by long press
SET
button and the screen shows “
SAL
”.
Then, press
MODE
button again to switch to the pressure setting mode, screen
shows “
P
”.
HOLD:
↑to
increase
ADJ:
↓to
decrease
