23
CALIBRA
TION
• Submerse the probe into
HI7040
Zero Oxygen solution and stir gently for 2 to 3 minutes. The “Not
Ready” message is displayed.
• Once the reading has stabilized, the countdown timer will count down until the display shows the
“Ready” message.
• Press
Confirm
to accept the calibration point.
• Press
OK
to return to the “Calibration” menu.
• Press
Measure
to return to the measurement screen.
Note:
The user can perform a single-point calibration by pressing ESC after the first point is accepted.
If the DO input is not within the acceptable range, the message “Invalid input” is displayed.
SINGLE-POINT CUSTOM % SATURATION CALIBRATION
To select the custom value:
• Press
Cal. Point
, then
Custom
.
• A text box will be displayed. Use the alphanumeric keypad to enter the value, then press
Accept
.
Note:
Only a one-point calibration is available when using a custom calibration point.
DO PROBE CONCENTRATION (HI764103)
From the
Calibration
menu, use the
/
keys to highlight
DO
concentration and then press
Select
.
• From the “DO calibration” menu, select the “DO concentration” option, insert the known
concentration. Allow the sensors to reach thermal equilibrium with the solution. Stir or agitate, if
possible, to keep fresh solution in front of the membrane and press
OK
.
• When the reading is stable, the stability timer will count down and
Confirm
will appear. Press
Confirm
to accept the value.
• When the messages “Storing” and “Calibration completed” appear, the calibration is completed.
To return to the “Calibration” menu, press
OK
.
• To return to the main menu, press
ESC
twice.
RESTORING FACTORY CALIBRATION
When a new DO probe or membrane is being used some of the warning messages are based on the
previous calibration. Restoring factory calibration will delete the user calibration and restore the factory
default calibration. Use the
/
keys to highlight
Restore factory calib
. and then press
Select
.