32
CALIBRA
TION
6. Wait a few minutes for the measurement to stabilize. Use the arrow keys to select “Custom ORP”
and press
Select
to start the calibration. A text box window will appear. Use the keypad to enter
the value of the solution at the current temperature. Press
Accept
to confirm calibration point.
7. 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.
8. The message “Storing” followed by “Calibration completed” will be displayed. Press
OK
to
return to the calibration menu or
Measure
to return to the measurement screen.
8.4. CONDUCTIVITY CALIBRATION
Conductivity calibrations are used to correct for variations in cell factors. Oily coatings and biological
contaminations can cause changes in the cell geometry. The EC electrodes are located inside two small
channels on the bottom of the sensor. They can be cleaned with the small brush from the maintenance
kit. A mild detergent can be used to remove oily coatings. Flush the electrodes with water thoroughly
after cleaning.
From the “Calibration” menu select “Single param. calibration” and then “Conductivity”.
Options:
•
Conductivity
: Perform a one-point calibration using a standard solution. The calibration is
temperature compensated.
•
Absolute conductivity
: Perform a one-point calibration with a known conductivity solution that is
not temperature compensated.
•
Salinity
: Perform a one-point calibration with a known salinity solution (PSU).
•
Restore factory calib.
: Restore the factory calibration if a new sensor has been installed.
Note:
To improve accuracy, choose a calibration standard near the sample conductivity.
Conductivity Calibration Procedure
1. Remove the shield from the probe. Rinse the probe with purified water.
2. Fill the calibration beaker 2/3 full with the conductivity standard solution.
3. Immerse the sensors in solution. Raise and lower the probe several times. Discard this solution.
4. Fill the calibration beaker 2/3 full with the conductivity standard solution.
