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16. Troubleshooting
16.1 General Errors
Error Message
Possible Causes
Remedy
Factory Calibration
Data Failure.
mV and Temperature
Readings Inaccurate
The EEPROM chip which
contains the factory calibration
information has failed.
The unit must be returned to TPS for
service.
mV & Temperature readings may be up to
10% incorrect.
Specific Ion and pH readings will be
accurate after a 2-point calibration (use
manual temperature compensation).
EEPROM Write Failure
Return to Factory for
Service
User calibration settings have
been lost or corrupted.
Switch the meter OFF and switch back ON.
If the problem persists, return the unit to
TPS for service.
16.2 Specific Ion, pH and mV Troubleshooting
Symptom
Possible Causes
Remedy
Unit fails to calibrate, even
with new probe.
Calibration settings outside of
allowable limits due to previous
failed calibration.
Initialize the unit. See section 14.
1 Point calibration fails.
(Specific Ion offset causes
over-range reading, or pH
asymmetry is greater than
±1.00 pH.)
1.
Reference junction blocked.
2.
Reference electrolyte
contaminated.
Clean reference junction, as per instructions
supplied with the pH or reference electrode.
Flush with distilled water and replace
electrolyte.
2 Point calibration fails.
(Specific Ion slope is less
than 50%, or pH slope is
less than 85.0%.)
1.
Specific Ion standards or pH
Buffers not correctly set.
2.
Ion sensor surface or pH
glass bulb not clean.
3.
Electrode is aged.
4.
Connector is damp.
5.
Specific Ion standards or pH
Buffers are inaccurate.
Ensure that you are using Specific Ion
standards as per the Standards set-up (see
section 3.2).
For automatic pH buffer recognition, ensure
that you are using buffers that match the
selected buffer set (see section 4.2).
Otherwise, ensure that the buffer value is
entered correctly at pH calibration.
Clean glass bulb as per instructions
supplied with the electrode.
Attempt rejuvenation, as per instructions
supplied with the electrode. If not
successful, replace electrode.
Dry in a warm place.
Replace standards or buffers.
Unstable readings.
1.
Reference Electrolyte
chamber needs to be refilled.
2.
Reference junction blocked.
3.
Glass bulb not clean.
4.
Bubble in glass bulb.
5.
Faulty connection to meter.
6.
Reference junction not
immersed.
7.
KCl crystals around
reference junction, inside the
electrolyte chamber.
Refill with saturated KCl filling solution.
Clean reference junction, as per instructions
supplied with the electrode.
Clean glass bulb as per instructions
supplied with the electrode.
Flick the electrode to remove bubble.
Check connectors. Replace if necessary.
Ensure that the reference junction is fully
immersed. See diagrams in sections 3.3 &
4.3.
Rinse electrolyte chamber with warm
distilled water until dissolved. Replace
electrolyte.
Inaccurate readings, even
when calibration is
successful.
Reference junction blocked.
Clean reference junction, as per instructions
supplied with the electrode.
Displays 7.00 for all
solutions.
Electrical short in connector.
1.
Check connector. Replace if necessary.
2.
Replace electrode.
Displays 4-5 pH for all
solutions.
pH electrode glass bulb or
internal stem cracked.
Replace pH electrode.