Hach Polymetron 9582sc, Руководство пользователя, Страница: 20 / 28

Problem Probable cause Resolution
Important instability
in measuring mode.
There is water or humidity in the sensor
cable connector. Dry the sensor cable connector inside and
out, and install finger tight.
Incorrect connection.
Check the sensor connection to the
controller module.
There are bubbles close to the cathode.
Refill with electrolyte and check there are
no bubbles at the bottom of the sensor
body.
The sensor has been violently shaken.
Check the fixation and stability of the
sensor.
Electromagnetic interferences close to the
sensor or controller cable. Find a better place for the cable and check
the EMC levels.
Temporary interference with other gases. Mainly with H
2
S.
Flow rate too low (4 mL/h minimum). Increase sample flow.
Sludge from a heterogeneous sample has
damaged the membrane. Install a deflector or change the sensor
location.
Pressure variation in the line.
Make sure the sensor is used at
atmospheric pressure.
Lack of accuracy.
The permeability of the membrane has
changed (dirt deposits). Calibrate the analyzer and check if the
concentration is back to normal.
Electrolyte pollution.
Check the screw-in parts (membrane, filling
screw) and change the electrolyte and the
membrane.
Electrolyte leaking.
Check the screw-in parts (membrane, filling
screw) and change the electrolyte and the
membrane.
Interferences, mainly with H
2
S.
If the level of H
2
S (or other pollutant) is
stable, take its concentration into account to
determine the dissolved O
2
concentration.
Error during calibration or incorrect
calibration.
Calibrate again to check the parameters. If
the error persists check the calibration
current (too high, too low or unstable) and
the concentration in air. Refer to the
problems described above.
There are bubbles close to the cathode.
Refill with electrolyte and check there are
no bubbles at the bottom of the sensor
body.
Flow rate too low (4 mL/h minimum). Increase sample flow.
The sample temperature or pressure is out
of specification. Change the sensor location or modify the
sample so that it is within specification.
Sludge or particles on the cathode.
Clean the cathode with a soft and
absorbent tissue. Change the membrane.
The sensor current
is null during
measurement.
There is no electrolyte in the sensor
(leakage). Check the screw-in parts (membrane, filling
screw) and change the electrolyte.
Sensor cable is disconnected or poorly
connected. Check cable connections on the module
and the sensor connector in the controller.
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