Concal - wtw pH/Oxi 340i Operating Manual

Operation
Two-point calibration
30

4.3.3 ConCal

For this procedure, use two buffer solutions:
l pH 7.0 ± 0.5
l any other buffer solution
Note
Skip the steps 2 and 8 if you use a pH electrode with a temperature
sensor or the temperature sensor of a D. O.probe.
1 Press the <CAL> key repeatedly until the ASY display and the
Cal function display appears. The sensor symbol displays the
evaluation of the last calibration (or no sensor symbol in the de-
livery state or after the measurement parameter has been re-
set).
TDS U pH O
S
A S Y
1
Time Baud
8 2 4
Day.Month No.
Year Ident
Tref25 Tref20 AutoCal DIN
LoBat nLF Lin Cal AutoCal TEC
2 If required, enter the temperature of the first buffer solution with
< > < > while keeping the <RUN/ENTER> key depressed.
3 Immerse the pH electrode in the first buffer solution (pH 7.0 ±
0.5 in two-point calibration).
4 Press the <RUN/ENTER> key.
The measured pH value appears on the display.
5 Set the measured value to the nominal pH value of the buffer
solution (at the current temperature) with < > < >.
6 When the measured value is stable, press the <RUN/ENTER>
key. The value of the asymmetry appears.
7 Press the <RUN/ENTER> key. SLO appears.
Note
At this point, the ConCal calibration can be broken off with <M>. This
corresponds to a single-point calibration. When doing so, the instru-
ment uses the Nernst slope (-59,2 mV/pH at 25 °C) and the fixed asym-
metry of the electrode.
Sal
mV/pH
% mg/l
m S/
cm
mbar M cm
1/ cm Sal
8
°
C
/
% K
TP
° F
Auto Store
ARng
AR RCL
pH/Oxi 340i