ELMETRON CX-401, Руководство пользователя

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9. CHECKING THE ELECTRODE CONDITION
After pH electrode calibration the meter calculates its parameters: offset in
pH units and slope defined also as efficiency in percents.
The electrode offset may be defined in pH or mV units.
An ideal electrode immersed in the 7.00 pH buffer before calibration should
indicate 7.00 pH which equals 0.00 mV. If the reading is different, it informs
that the electrode has an offset, which may be reduced by calibration. The
information about the offset in mV may be obtained by converting the reading
in pH. At 20
0
C each pH unit corresponds to 58,168 mV. If the electrode has
0,2 pH offset, multiply it by 58,168 mV to obtain the electrode potential value
in mV (SEM – Standard Error of Measurement). In the given example it will
be equal 11,634 mV.
The SEM parameter may be also checked by immersing the electrode in 7.00
pH buffer and switching the meter to measurement in mV.
Blinking of the electrode symbol ( , , ) after calibration informs that the
electrode has lost its efficiency and that in a short time its calibration will not
be possible. After entering the mode of the electrode’s number changing
symbol is displayed below the electrode number (Pic. 15.).
Nale
ż
y przygotowa
ć
now
ą
elektrod
ę
.
Pic. 15.