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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 Section 6.7.
4. Please check whether pH probe is damaged or
broken. If so, please replace with a new one.
5. The pH sensor is severely contaminated. Please
use a soft brush with soap water or Electrode
Cleaning Solution (SKU: AI1166) to clean it
thoroughly. Then soak it in 3M KCL 3-5 hours
before performing calibration again.
is pressed before
measurement
is fully stabilized.
Wait for to stay on screen before pressing
During calibration, readings
being unstable for over 3
minutes.
1. Please check whether pH probe is damaged or
broken. If so, please replace with a new one.
2. T h e g l a s s b u l b o r j u n c t i o n i s s e ve re l y
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 probe is aged (used for over a year and has a
much slower response). A replacement is needed.
pH probe 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 probe is damaged or
broken. If so, please replace with a new one.
4. The probe is aged (used for over a year and has a
much slower response). A replacement is needed.
5. The probe is invalidated (Er4/Er5 repetitively
appears, and problems 1, 2, 3 are excluded). Probe
replacement is needed.
pH probe slope out of range
(<85% or >110%)
The calibration reminder is
triggered. It’s time to perform a
new pH calibration.
Perform pH calibration or cancel calibration reminder
in ZenTest App settings.
