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6.8 For the self-diagnosis information, please refer to the table below:
Symbol
Self-Diagnosis
information
Potential problems and how to fix
The pH calibration
solution cannot be
recognized by the meter.
1.
Make sure the probe is fully immersed in the
calibration solution.
2.
Check if calibration solution is expired or polluted.
3.
1st point of pH calibration must be pH 7.00 or
6.86. See 6.2 (1).
4.
Please check whether pH electrode is damaged
or broken. If so, please replace with a new one.
5.
The glass bulb or junction is severely
contaminated. Please use a soft brush with soap
water to clean it thoroughly. Then soak it in 3M
KCL 3-5 hours before performing calibration
again.
Is pressed before
measurement is fully
stable
Wait for
to come up and stay on screen
before pressing
During calibration,
readings being unstable
for over 3 minutes
1.
Please check whether pH electrode is damaged
or broken. If so, please replace with a new one.
2.
The glass bulb or junction is severely
contaminated. Please use a soft brush with soap
water to clean it thoroughly. Then soak it in 3M
KCL overnight before performing calibration again.
3.
The electrode is aged (used for over a year and
has a much slower response). A replacement is
needed.
pH electrode zero
electric potential out of
range
(<-60mV or >60mV)
1.
Check whether pH buffer solutions comply with
the USA or NIST standard.
2.
Check whether pH buffers are expired or
contaminated.
3.
Please check whether pH electrode is damaged
or broken. If so, please replace with a new one.
4.
The electrode is aged (used for over a year and
has a much slower response). A replacement is
needed.
5.
The electrode is invalidated (Er4/Er5 repetitively
appears, and problems 1, 2, 3 are excluded). A
replacement is needed.
pH electrode slope out of
range (<85% or >110%)
The calibration reminder is
triggered. I
t’s time to
perform a new pH
calibration
Perform pH calibration or cancel calibration reminder in
ZenTest App settings.
