Metrohm 914 pH / Conductometer - Manual (Page 73)

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6 Troubleshooting
pH Meter/Conductometer
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Problem Cause Remedy
The pH value or the tem-
perature of the measuring
solution is not stable. ￭ Measure under exclusion of air.
￭ Regulate the measuring solution's tempera-
ture.
Conductivity is too low
because of an unsuitable
sensor. ￭ Use a suitable sensor.
Measurement takes place
in an organic solution. ￭ Use a suitable sensor.
Non-Metrohm power sup-
ply unit used for charging
the battery. ￭ Use only the supplied power supply unit
during measurement operation.
The measured value
is evidently wrong. pH calibration is faulty. ￭ Check/repeat calibration.
￭ Check/replace the buffer.
￭ Check the buffer selection in the settings.
Conductivity calibration is
faulty. ￭ Check/repeat calibration.
￭ Check the value for the standard.
￭ Check the value for the reference tempera-
ture.
￭ Check the value for temperature compen-
sation.
The temperature input is
wrong. ￭ Enter the correct measuring temperature.
The wrong temperature
sensor type is selected. ￭ Check the temperature sensor type (Pt1000
or NTC) and select the correct one, if nec-
essary.
The glass membrane or the
diaphragm is contami-
nated. ￭ Clean the membrane or the diaphragm fol-
lowing the instructions in the correspond-
ing leaflet.
The electrolyte is overaged. ￭ Replace the electrolyte.
The sensor is defective. ￭ Replace the sensor.
The slope is insuffi-
cient during calibra-
tion. The glass membrane or the
diaphragm is contami-
nated. ￭ Clean the electrode following the instruc-
tions in the leaflet.