Hach ISEF121 Series, User Manual

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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
in the solution. 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 value of the
standard solution.
The meter accepts
or rejects the result.
Section 8 Maintenance
Regular maintenance is necessary for the best accuracy, stabilization time and life of the probe.
Keep the probe clean between measurements.
8.1 Clean the probe
Clean the probe regularly to remove mineral or sample buildup on the sensing element. Symptoms of
contamination:
• Incorrect or irregular readings
• Slow stabilization times
• Calibration errors
• Sample material stays on the probe
1. Rinse the probe with deionized water. Dry the probe with a lint-free cloth.
2. Clean the sensing element as follows:
a. Lightly polish the sensing element with a small quantity of plain fluoride toothpaste (no teeth
whiteners or abrasives). Use a circular movement and polish until the sensing element is
clean.
b. Fully rinse with deionized water.
c. Soak the probe in isopropyl alcohol for 30 minutes.
d. Rinse the probe with deionized water.
e. Condition the probe. Refer to Preparation for use on page 5.
3. Soak the probe for 30 minutes in a 1-mg/L fluoride standard solution.
8.2 Storage
Keep the sensor protection cap on the probe during storage to prevent damage to the sensing
element.
Note: Make sure to condition the probe after long-term storage. Refer to Preparation for use on page 5.
1. Rinse the probe with deionized water. Dry the probe with a lint-free cloth.
2. Make sure that the probe sensor is dry, then install the sensor protection cap. Refer to Product
overview on page 3.
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