16.0 Troubleshooting guide
Trouble
Nutrient reading
low
Temperature
reading
inaccurate
pH reading
inaccurate
Display shows
'Err' during
calibration
No display
pH displays 'or'
pH displays 'ur'
temp displays
'or'
temp displays
'ur'
conductivity
displays 'or'
A display shows
_ _ _ _
15
Reason
Contaminated conductivity/temperature
probe.
Temperature of conductivity/
temperature probe and solution
different.
Temperature of conductivity/
temperature probe different to solution
temperature.
Contaminated pH probe / glassware
not clean.
Using factory default calibration.
Calibration old.
Broken glass bulb, tube or connector.
pH probe damaged or old.
An attempt was made to calibrate with
pH 4.0 or pH 10.0 calibration solution
more than one hour after calibration
with the pH7.0 solution.
Old or contaminated solutions used for
calibration.
Dirty or contaminated pH probe.
pH probe tip been allowed to dry.
pH probe damaged or old.
Mains not switched on.
Power adaptor not plugged into the
Guardian Monitor.
Over range pH.
Under range pH.
Over range temperature.
Under range temperature.
Over range conductivity/nutrient.
EC and pH cannot be determined as
temperature range is over/under.
(see technical specification range
section 17.0).
Correction
Clean conductivity/temperature probe
(see section 13.0) .
Wait 5-10 minutes for conductivity/
temperature probe to reach solution
temperature.
Wait 5-10 minutes for conductivity/
temperature probe to reach solution
temperature.
Clean pH probe (see Section 14.0); then
calibrate (see Section 10.0).
Calibrate pH probe (see section 10.0).
Calibrate pH probe (see section 10.0).
Check pH probe for damage.
Replace pH probe.
Calibrate to pH 7.0 again then do pH 4.0
/ pH 10.0 calibration within one hour.
Use fresh calibration solutions.
Clean pH probe (see section 14.0).
Hydrate pH probe (see section 15.0).
Replace pH probe.
Switch mains power on.
Plug power adaptor into the base of the
Guardian Monitor labeled 'Power Input'.
Solution > 14.0 pH.
Solution < 0.0 pH.
Check pH probe connection. pH probe
could be faulty. Guardian Monitor could
be wet inside.
Solution >51 °C / 122 °F.
Solution <0 °C / 32 °F.
Conductivity/temperature probe or
Guardian Monitor faulty.
Over range conductivity >9.9 EC, 99 CF,
1990 ppm. Conductivity/temperature
probe or Guardian Monitor faulty.
Test pH probe in calibration solutions
and conductivity/temperature probe in
a known conductivity standard solution
to eliminate these as a cause of this
problem. Check solution tank/reservoir
for problems.
Need help?
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