Xylem handylab pH LF 12 - Manual (Page 32)

Operation handylab pH/LF 12
32 ba75370e03 11/2009
4.3.3 ConCal
Two-point
calibration
For this procedure, use two buffer solutions:
z pH 7.0 ± 0.5
z any other buffer solution
Note
Skip the steps 2 and 9 if you use a pH electrode with a temperature probe or
the temperature probe of a conductivity measuring cell.
Note
At this point, the ConCal calibration can be broken off with <M>. This corre-
sponds to a single-point calibration. When doing so, the instrument uses
the Nernst slope (-59,2 mV/pH at 25 °C) and the fixed asymmetry of the elec-
trode.
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).
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.
/ K
cm
Sal
1 S
O U
8
° F
%
1/cm
mV/pH
S/ m cm
M
% mg/l
mbar
Lin
Tref25
nLF
Time Baud
Day.Month No.
Ident Year
LoBat
AutoCal DIN
AutoCal TEC RCL
Auto Store
ARng AR
TDS Sal
Tref20
8 4 2
S Y A
pH
Cal
° C
TP