21
Fluoride Ion Selective Electrode User Guide
3. Prepare the standards as described in the Direct Calibration
section of this user guide. Prepare calibration standards for
testing by mixing a portion of the standard with an equal
portion of low level TISAB in a non-glass beaker. Stir the
solution.
4. Ensure that the Autoblank mode is enabled in the meter
setup mode.
5. Rinse the electrode with deionized water, blot dry and
place into the beaker with the least concentration standard.
While stirring the solution, select the meter calibration
mode and wait for a stable reading. Adjust the meter to
display the value of the standard, as described in the meter
user guide.
6. Repeat step 5 for the second and third standards and
complete the calibration, as described in the meter user guide.
7.
Record the resulting slope value. The absolute value of
millivolt difference should be greater than 54 mV.
8. Measure equal amounts of the sample and low level TISAB
into a non-glass beaker. Stir the solution.
9. Rinse the electrode with deionized water, blot dry and place
into the beaker with the prepared sample. Continue stirring
the solution and wait for a stable reading. The concentration
of the sample will be displayed on the meter.
