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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 t
ime to
perform a new pH
calibration
Perform pH calibration or cancel calibration reminder in
ZenTest App settings.
7. pH Measurement
How to take pH measurements
Short press
to turn on the tester. Rinse the probe in distilled water, shake off excess water.
Insert the probe in your sample solution, make a quick stir and hold still. Record the reading when it
