Hach PHC745, Руководство пользователя

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Section 9 Troubleshooting
Keep the probe clean and in the recommended storage solution when not in use for the best
accuracy, stabilization time and life of the probe.
Problem Possible cause Solution
Decreased probe performance
causes slow stabilization and
prevents accurate calibrations or
measurements.
The glass sensor is dirty. Clean and condition the probe.
Refer to
Clean the probe
on page 12.
The reference junction is
clogged. Clean and condition the probe.
Refer to
Clean the probe
on page 12.
The filling solution has
contamination. Replace the filling solution.
Refer to
Replace the filling
solution on page 16.
The probe is not conditioned
to the sample sufficiently. Condition the probe. Refer to
Preparation for use on page 5.
The glass sensor has become
dry. Soak the probe tip in buffer
solutions. Refer to
Soak
procedure for dry probes
on page 17.
The calibration slope of the
probe has changed. Increase the accepted slope
limit settings if possible, or
contact technical support.
Sample properties cause slow
stabilization or inaccurate
measurements.
The sample absorbs carbon
dioxide (CO
2
) from the air,
which causes the pH value to
slowly decrease in low ionic
strength (LIS) or high purity
samples.
Use the LIS chamber for
LIS/high purity samples to
prevent CO
2
absorption.
The sample temperature is
low, or there is a large
temperature difference
between samples. Increase the sample
temperature or adjust the
temperature of different
samples to be the same (within
2 °C (3.6 °F)).
18 English