Bluelab Guardian Monitor - Manual (Page 15)

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