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39
CALIBRA
TION
Conductivity:
The user can perform a one-point calibration using a standard solution. The
calibration is temperature compensated.
Absolute Conductivity: The user can perform a one-point calibration with a known conductivity
solution that is not temperature compensated.
Salinity:
The user can perform a one-point calibration with a known salinity solution (PSU).
Restore Factory Calib.: The user can restore the factory calibration if a new sensor has been installed.
Notes:
The probe shield or calibration beaker must be used during calibration.
When the Conductivity is calibrated, also the Absolute Conductivity and Salinity is calibrated, and
vice versa. A Conductivity calibration is recommended.
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.
Note:
If the tutorial mode is enabled, press Tutorial and follow the messages on the screen.
Conductivity Calibration
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 the solution. Raise and lower the probe several times then discard this
solution.
4. Fill the calibration beaker 2/3 full with the conductivity standard solution.
5. Slowly place the sensors in the solution. Dislodge bubbles that may adhere to the sensors.
6. Screw the calibration beaker completely onto the probe body. Some solution may overflow.
7. Use the arrow keys to select “Conductivity” and press
Start
to start the calibration.
8. If necessary, press
Cal. point
to select the correct standard. To use a custom standard, press
Custom
. A text box window will appear. Use the keypad to enter the value of the standard
(100 to 200000
µ
S/cm) at the current temperature. Press
Accept
to confirm the standard value.
9. Once the reading has stabilized, the stability timer will count down until the display shows the
“Ready“ message.