wtw pH 197i Operating Manual page 24

Calibration
pH
S mV /
1 A S Y
O % mg/l
S/
m
Sal
1/ cm
Time Baud
8 2 4 8
C
°
Day.Month No.
%
Year Ident
Tref25 Tref20 Auto Store REL1
LoBat nLF Lin Oxi Cal TEC ARng AR
pH S mV /
7 7 0 2
O % mg/l
S/
m
Sal
1/ cm
Time Baud
8 2 4 8
C
°
Day.Month No.
%
Year Ident
Tref25 Tref20 Auto Store REL1
LoBat nLF Lin Oxi Cal TEC ARng AR
pH S mV /
4 S L O
O % mg/l
S/
Sal m
1/ cm
Time Baud
8 2 4 8
C
°
Day.Month No.
%
Year Ident
Tref25 Tref20 Auto Store REL1
LoBat nLF Lin Oxi Cal TEC ARng AR
pH S mV /
7 $ 5 8
O % mg/l
S/
m
Sal
1/ cm
Time Baud
8 2 4 8
C
°
Day.Month No.
%
Year Ident
Tref25 Tref20 Auto Store REL1
LoBat nLF Lin Oxi Cal TEC ARng AR
pH S mV/
5 9 4
-
O % mg/l
S/
Sal m cm
pH S mV /
C T 3
1
O % mg/ l
S/
Sal m
24
ConCal procedure:
l Connect the pH electrode to the measuring instrument.
l Press the <CAL> key repeatedly until the ASY display indicator and the
pH
Cal function display appear. The sensor symbol displays the evaluation
cm
of the last calibration (or no sensor symbol in the delivery state or after
Sal
the measuring parameters have been reset).
/ K
TP
l Immerse the pH electrode in the first buffer solution
REL2
RCL
(pH 7.0 ± 0.5 in two-point calibration).
l When measuring without a temperature sensor:
Enter the temperature of the first buffer solution
with <L> <M> while pressing the <RUN/ENTER> key.
l Press the <RUN/ENTER> key.
pH
The measured pH value appears on the display.
cm
l Set the measured value to the nominal pH value of the buffer solution (at
Sal
the current temperature) with <L> <M>.
/ K
TP
REL2
l When the measured value is stable, press the <RUN/ENTER> key. The
RCL
value of the asymmetry appears.
l Press the <RUN/ENTER> key. SLO appears.
Note
pH
At this point, the ConCal calibration can be terminated with
cm <M>. This corresponds to a single-point calibration. To do
Sal this, the instrument uses the Nernst slope (-59.2 mV/pH at
/ K
TP
25 °C) and determines the asymmetry of the electrode.
REL2
RCL
l To continue the two-point calibration, immerse the pH electrode in the
second buffer solution.
l When measuring without a temperature sensor:
Enter the temperature of the second buffer solution
with <L> <M> while pressing the <RUN/ENTER> key.
l Press <RUN/ENTER>.
pH
l Set the measured value to the nominal pH value of the buffer solution (at
cm
the current temperature) with <L> <M>.
Sal
/ K
TP
REL2
RCL
l When the measured value is stable, press the <RUN/ENTER> key. The
pH
instrument displays the value of the slope and the calibration evaluation.
l Press <RUN/ENTER>. The instrument displays the value of the
pH
asymmetry.
cm
l Switch to the measuring mode with <M>.
pH 197i