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Operational Guide
50
100% Saturated Calibration
It is suggested to perform the slope calibration in water-saturated air.
Pour water into a small beaker.
Rinse the polarized probe with clean water.
Dry the probe tip and allow a few seconds for the LCD reading to stabilize (probe
in air).
Suspend probe with membrane just over the beaker of water.
Press
CAL
.
The “ ” tag will be displayed along with “WAIT” blinking
on the LCD until the reading is stable.
When the reading is stable and is within the limits,
“CFM” tag starts blinking. Press
CFM
to confirm the
100.0 % DO calibration.
Press
CAL
to leave calibration after the first point. The instrument will display
“SAVING” message and it will return to measurement mode memorizing the
slope calibration data
Zero Calibration
Press
CAL
or continue with calibration after confirming
first point. The meter will display “WAIT” and “0.0 %”
will be displayed in lower right corner.
Submerse the probe membrane and temperature
sensor into the beaker containing HI 7040 Zero
Oxygen solution and stir gently for 2-3 minutes, the
reading will go down.
When the reading is stable and stops decreasing,
“CFM” tag starts blinking. Press
CFM
to confirm the
0.0 % DO calibration.
The instrument will display “SAVING” message and it
will return to measurement mode. Rinse probe tip off
in water before taking measurements in samples.
Dissolved
Oxygen
Calibration
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