Manual

XX. TROUBLESHOOTING CHART
37
SYMPTOM POSSIBLE CAUSE
Meter won’t turn ON •Batteryweak.
Inaccurate pH readings
(D-6)
•pHcalibrationneeded.
•ContaminationfromresidualpHbuffers
or samples in sensor well.
•CalibrationwithexpiredpHbuffers.
No response to pH
changes (D-6)
•pH/ORPsensorbulbiscracked.
•Electromechanicalshortinsidethe
sensor body.
pH Zero Point calibration
will not adjust down to pH
7.0 (D-6)
•pH/ORPsensor’sinternalKClsolution
is depleted or contaminated.
pH readings drift or
respond slowly to changes
in buffers/samples (D-6)
or
“FAC” is displayed
repeatedly
•TemporaryconditionduetothepH/
ORP sensor’s memory of solution in left
in the sensor well for long periods.
•Bulbdirtyordriedout.
•Referencejunctioncloggedorcoated.
Unstable Conductivity or
TDS reading
•Dirtyelectrodes.
Unstable Resistivity
readings
•Dirtyelectrodes.
•Contaminationofsampledueto
exposure to air resulting in samples
withresistivity>1MΩ.
Unable to calibrate
Conductivity or TDS
•Filmordepositsonelectrodes.
Resistivity readings much
lower than expected
•Contaminationfromprevioussampleor
from pH sensor well.
•TestSampleiscontaminatedby
Carbon dioxide absorbed from the air
(commonly caused by using a standing
sample).