Hach-Lange NISE sc - Manual (Page 37)

37
Troubleshooting
6.3 Troubleshooting
6.3.1 Troubleshooting during operation
Symptom Possible cause Corrective measures
Incorrect
measurement values
Calibration too old; calibration was not suitable for
the particular application; large change in the waste
water matrix Perform a suitable calibration.
Refer to
4.6 Calibration/matrix correction,
Page 25
Severely contaminated membranes and/or
reference electrode
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
Sensor membrane damaged Check the sensor installation/
replace the sensor cartridge
Reference element damaged
NO3 mV RANGE! (Nitrate mV value is out of
measurement range)
1,3
Replace the sensor cartridge
CL mV RANGE! (Chloride value is out of
measurement range)
1,3
REF1 RANGE! (measuring range exceeded on
1st reference value)
REF2 RANGE! (measuring range exceeded on
2nd reference value)
TEMPERATURE (Temperature value is out of
measurement range) Replace the sensor cartridge/check the
waste water temperature
CARTRIDGE OLD (sensor cartridge more than
1
year old)
Replace the sensor cartridge
Moisture at the contacts of 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.
Incorrect
measurement values
Moisture inside the measurement probe/faulty
sensor electronics
Check the sensor electronics by using the test
cartridge (
section 7.2, page 39 ).
1 Select SENSOR MENU > DIAG/TEST >
SERVICE > TEST CARTRIDGE > Test
cartridge
ready? Press ENTER
2 If all channels are confirmed with OK, the
sensor electronics are operational:
Test cartridge
OK
ENTER
If the test cartridge data is not within this
range and/or if the test cartridge check is not
successful, contact the service department.
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)
Switch off potassium/chloride compensation
(in the configuration menu - then potentially
enter a fixed value for potassium/chloride)