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24.3 pH Troubleshooting
Symptom
Possible Causes
Remedy
Unit fails to calibrate, even
with new probe.
Calibration settings outside of
allowable limits due to previous
failed calibration.
Reset the unit. See section 22.
1 Point calibration fails
(Asymmetry is greater than
+/-1.00 pH).
1. Reference junction blocked.
Clean reference junction, as per instructions
supplied with the electrode.
2 Point calibration fails
(Slope is less than 85.0%).
1. Buffer set incorrectly
2. Glass bulb not clean.
3. Electrode is aged.
4. Connector is damp.
5. Buffers are inaccurate.
For automatic buffer recognition, ensure
that you are using buffers that match the
selected buffer set (section 21).
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 buffers.
Unstable readings.
1. Reference junction blocked.
2. Glass bulb not clean.
3. Bubble in glass bulb.
4. Faulty connection to meter.
5. Reference junction not
immersed.
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 bulb AND the reference
junction are fully immersed, as per diagram
in section 9.1.
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.
Glass bulb or internal stem
cracked.
Replace electrode.
24.4 Temperature Troubleshooting
Symptom
Possible Causes
Remedy
Temperature inaccurate and
cannot be calibrated.
1. Faulty connector.
2. Faulty temperature sensor
(inside Conductivity sensor).
Check the connector and replace if
necessary.
Fit new Conductivity/Temperature sensor.
Displays flashing “
OVR
O
c
”
when temperature probe
plugged in.
1. Faulty
Cond/Temp
socket.
2. Faulty temperature sensor
(inside Conductivity sensor).
Return the instrument to the TPS factory for
service.
Fit new Conductivity/Temperature.
24.5 Pump Troubleshooting
Symptom
Possible Causes
Remedy
Pump(s) do not prime, lose
their prime, or pumping at a
very low flow rate.
1. Input tube incorrectly fitted,
causing air leak.
2. Worn pump squeeze tube.
3. Faulty pump.
See section 11.1 for details on correct input
tube fitment.
Fit replacement pump tube (part no
116352). See details in section 11.3.
Return to the TPS factory for repair.
A & B pumps do not
produce the same output
1. Output flow rate of each
pump is different.
Adjust A & B Fine Tune control until a 1:1
A & B ratio is achieved. See section 11.1.
Display shows “
ShutOFF
”
for Conductivity and/or pH
control status.
2. Control
ON
time set too
short and/or
OFF
time set
too long.
3. Pump(s) have insufficient
capacity to keep up with
demand.
See section 20 for details on ShutOFF
function and suggested remedies.
Alternative higher capacity pump(s) are
required.
