Hach PHC108, Руководство пользователя, Страница: 13 / 18

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 9.
The glass sensor has become
dry. Clean and condition the probe.
Refer to
Maintenance on page 9.
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)).
Procedure problem causes
slow stabilization and prevents
accurate calibrations or
measurements. The probe is not conditioned
to the sample. Soak the probe in the sample
before sample measurements.
Refer to
Preparation for use
on page 5.
Air bubbles are around or
below the probe tip. Carefully tap or shake the probe
to remove air bubbles.
The electrical connection
through the reference junction
is not sufficient. Shake the probe in the solution
from side to side to refresh the
reference junction.
The stir speed is too slow or
too fast. Try a different stir speed.
An incorrect buffer solution
was used or the buffer solution
has contamination. Use the specified buffer solutions
of good quality.
Section 10 Consumables
Note: Product and Article numbers may vary for some selling regions. Contact the appropriate distributor or refer to
the company website for contact information.
Description Quantity
2
Item no.
Hach pH electrode storage solution 500 mL 2756549
3 M KCl solution 50 mL
3
2756559
2
Larger quantities are available for some items.
3
Larger quantities are available.
English 11