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6.6.7 Restore to factory default setting (P7)
(a) Short press in P6 to enter P7, see picture (4-8).
(b) Press or to choose , meaning that the parameters
have been restored to the producer setting mode, and return to
measurement mode after 2 seconds. Returning to factory default setting
is to restore the meter to theoretical value (zero potential pH is 7.00, slope
is 100%), and set all the parameters to default settings. When the meter’s calibration or measurement is
performing abnormally, users can use this function, and then calibrate and test again. Please note that
this function is irreversible once used.
6.7
Cleaning pH Electrode
1)
The measurement is only as accurate as the electrode is clean. Always thoroughly rinse off the
electrode before and after each test with pure water.
2)
For tough contaminants, soak the electrode in Apera electrode cleaning solution (AI1166) for at
least minutes. Then use a soft brush to remove the contaminants. Afterwards, soak the electrode
in 3M KCL soaking solution for at least 2 hours. Rinse it off, then re-calibrate the tester before
using again.
3)
For other special contaminants, refer to the table below:
Contamination
Cleaning Solution
Inorganic metal oxide
Dilute acid less than 1mol/L
Organic lipid, protein containing samples
Apera cleaning solution (AI1166)
Resin macromolecule
Dilute alcohol, acetone, ether
Paints
Dilute bleacher, peroxide
6.8
The Self-diagnose Information
During usage, the following icons may show up on LCD. This is the meter’s self-diagnose information,
which can help you understand what may go wrong with the meter or electrode.
6.8.1. The stable icon
-2.00 pH
or
19.99 pH
— this icon appears when the pH value exceeds the
measurement range. This icon will also show up when the electrode is not well connected with the meter
or when the electrode is not insertd into solution. This is a normal phenomenon.
6.8.2. — Electrode offset out of range (<-60mV or >60mV)