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17.3 Conductivity / TDS Troubleshooting
Symptom
Possible Causes
Remedy
Unit fails to calibrate, even
with new probe.
Calibration settings outside of
allowable limits due to previous
failed calibration.
Initialise the unit. See section 15.
Unit attempts Span
calibration instead of Zero
calibration.
Sensor has Zero error.
Thoroughly rinse sensor in distilled water
and allow to completely dry in air before
attempting zero calibration.
Clean the glass around the platinum plate
area. DO NOT rub the black platinised
surfaces.
Standard calibration fails,
and k factor is greater than
25%
above
the nominal
value.
1. Sensor is not immersed
correctly.
2. Sensor may have a build-up
of dirt or oily material on
electrode plates.
3. Platinum-black coating has
worn off.
4. Standard solution is
inaccurate.
5. Sensor is faulty.
6. Faulty instrument.
Immerse sensor at least to the vent hole in
the side of the sensor.
Clean sensor as per the instructions detailed
in section 18.2.1.
Sensor requires replatinisation as per
section 18.2.1. Alternatively, return to the
factory for replatinisation.
Replace standard solution.
Return sensor to factory for repair or
replacement.
Return to factory for repair.
Standard calibration fails,
and k factor is greater than
25%
below
the nominal
value.
1. Standard solution is
inaccurate.
2. Sensor may have a build-up
of conductive material, such
as salt.
3. Sensor is faulty.
4. Faulty instrument.
Replace standard solution.
Clean sensor as per the instructions detailed
in section 18.2.1.
Return sensor to factory for repair or
replacement.
Return to factory for repair.
Inaccurate readings, even
when calibration is
successful.
1. Sensor may have a build-up
of dirt or oily material on
electrode plates.
2. Platinum-black coating has
worn off.
Clean sensor as per the instructions detailed
in section 18.2.1.
Sensor requires replatinisation as per
section 18.2.1. Alternatively, return to the
factory for replatinisation.
Readings drift.
Sensor may have a build-up of
dirt or oily material on electrode
plates.
Clean sensor as per the instructions detailed
in section 18.2.1.
Readings are low or near
zero.
1. Sensor may have a build-up
of dirt or oily material on
electrode plates.
2. Sensor is not immersed
correctly.
3. Sensor is faulty.
4. Faulty instrument.
Clean sensor as per the instructions detailed
in section 18.2.1.
Immerse sensor at least to the vent hole in
the side of the sensor.
Return sensor to factory for repair or
replacement.
Return to factory for repair.
Reading does not change in
any sample being measured
Auto Stability Function has
frozen display (notice the ).
Turn Auto Stability Function OFF or re-
start sampling (see section 7).
Summary of Contents for smartCHEM-D
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