Hach ISEF121 Series, User Manual

Page: 8 / 18

5.2 Calibration procedure
1. Go to the
calibrate menu.
Select the probe, if
applicable. The
display shows the
standard solutions to
use for calibration.
2. Add 25 mL of
each standard
solution to plastic
beakers.
3. Add one Fluoride
Ionic Strength
Adjustor (ISA)
Powder Pillow to
each 25 mL of
standard solution.
Note: As an alternative,
add 5 mL of Fluoride
ISA Solution.
4. Add a stir bar to
the first standard
solution. Put the
standard solution on
an electromagnetic
stirrer. Stir at a
moderate rate.
5. Rinse the probe
with deionized water.
Dry the probe with a
lint-free cloth.
6. Put the probe in
the standard solution
with the sensor fully
submerged. Do not
put the probe on the
bottom or sides of
the beaker.
7. Shake the probe
from side to side to
remove air bubbles.
8. Stir for 30 to
60 seconds, then
read the fluoride
concentration of the
standard solution.
9. Do steps 3
through 8 to read the
value of the
remaining standard
solutions.
10. Save the
calibration.
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