Hach AN-ise SC Betriebsanleitung Seite 21

6.3 Troubleshooting
6.3.1 Troubleshooting during operation
Symptom
Calibration too old; calibration was not suitable for
the particular application; large change in the waste
water matrix
Severely contaminated membranes and/or
reference electrode
Sensor membrane damaged
Incorrect
measurement values
Reference element damaged
NO
Cl- mV is out of range!
Reference electrode 1 mV is out of range!
Reference electrode 2 mV is out of range!
Temperature is out of range!
The cartridge has expired.
Moisture at the contacts of the sensor cartridge
Moisture inside the measurement probe/faulty
sensor electronics
Check the sensor electronics by using the test
cartridge
1
2
Incorrect
measurement values
Potassium concentrations too high (e.g.: >700 mg/L
in the case of small ammonium concentrations) or
chloride concentrations too high (e.g.: >1000 mg/L
in the case of small nitrate concentrations)
Air bubbles, depth of immersion
Unstable
Moisture at the contacts of the sensor cartridge
measurement values
Sensor membrane damaged
Reference element damaged
English
Possible cause
1,3
mV is out of range!
3
1,3
(section 7.2, page 39).
Select Sensor menu > Maintenance > Service >
Cartridge test> Cartridge test. Press Enter
If all channels are confirmed with OK, the
sensor electronics are operational:
Test cartridge
Ok
Enter
Troubleshooting
Corrective measures
Perform a suitable calibration.
Refer to 4.6 Calibration/matrix correction,
Page 25
Clean the sensor cartridge using a brush
and/or rinse the sensor cartridge with clean
water (without cleaning agents), and wipe the
sensor cartridge carefully with a soft, clean
cloth.
Clean all components (membranes/reference
electrode/temperature sensor).
Install the cleaning unit
Increase the cleaning interval
Check the sensor installation/
replace the sensor cartridge
Replace the sensor cartridge
Replace the sensor cartridge/check the
waste water temperature
Replace the sensor cartridge
Dry the contact with a cloth or paper
Check the black gasket for damage and
make sure it is in the correct position.
Screw the 4 socket head screws tight.
If the test cartridge data is not within this
range and/or if the test cartridge check is not
successful, contact the service department.
Switch off potassium/chloride compensation
(in the configuration menu - then potentially
enter a fixed value for potassium/chloride)
Check the sensor installation
Check the cleaning unit configuration
Dry the contacts with a cloth or paper.
Check the black gasket for damage and
make sure it is in the correct position.
Screw the 4 socket head screws tight
Check the sensor installation/
replace the sensor cartridge
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