Xylem PH1970i PORTABLE PH METER User Manual
Page 22
Calibration
pH 1970i
22
ba75675e01
01/2007
AutoCal TEC / AutoCal DIN procedure:
The following example shows the AutoCal TEC calibration. In the
AutoCal DIN calibration, Cd... appears on the display instead of Ct....
Otherwise, both procedures are identical.
The selection of the calibration procedure, AutoCal TEC (display Ct1) or
AutoCal DIN (display Cd1) is made with the <CAL> key.
z
Connect the pH electrode to the measuring instrument.
z
Press the <CAL> key repeatedly until the Ct1 display indicator and the
Auto Cal TEC function display appear. The sensor symbol displays the
evaluation of the last calibration (or no sensor symbol in the delivery state
or after the measuring parameters have been reset).
z
Immerse the pH electrode in the first buffer solution.
z
When measuring without a temperature sensor:
Enter the temperature of the first buffer solution with <
▲
> <
▼
>.
z
Press <RUN/ENTER>. The AutoRead measurement begins. The
electrode voltage (mV) or the buffer nominal value (see C
ONFIGURING
)
appears on the display. When the measured value is stable, Ct2
appears.
Note
At this point, the AutoCal TEC calibration can be terminated
with <M>. This corresponds to a single-point calibration. To
do this, the instrument uses the Nernst slope (-59.2 mV/pH at
25 °C) and determines the asymmetry of the electrode.
z
To continue the two-point calibration, immerse the pH electrode in the
second buffer solution.
z
When measuring without a temperature sensor:
Enter the temperature of the second buffer solution with <
▲
> <
▼
>.
z
Press <RUN/ENTER>. The AutoRead measurement begins. The
electrode voltage (mV) or the buffer nominal value appears on the
display.
z
When the measured value is stable, the instrument displays the value of
the slope and the evaluation of the two-point calibration.
z
Press <RUN/ENTER>. The instrument displays the value of the
asymmetry.
Note
At this point, the AutoCal TEC calibration can be terminated
with <M>. This corresponds to a two-point calibration.
Store
AR
1
LoBat
nLF
Lin
Oxi
Tref25
Tref20
ARng
8
Time
Year
Ident
No.
Day.Month
Baud
Sal
cm
1/
K
/
%
RCL
REL2
pH
/
mV
m
cm
S/
%
mg/ l
Sal
O
S
pH
C
2 4 8
T 1
°
C
TP
REL1
Cal
TEC
Auto
Store
AR
1
LoBat
nLF
Lin
Oxi
Tref25
Tref20
ARng
8
Time
Year
Ident
No.
Day.Month
Baud
Sal
cm
1/
K
/
%
RCL
REL2
pH
/
mV
m
cm
S/
%
mg/ l
Sal
O
S
pH
C
2 4 8
T 2
°
C
TP
REL1
Cal
TEC
Auto
-
m
cm
S/
%
mg/ l
Sal
O
S
pH
5 9 4
pH
mV/
1
pH
cm
S/
mg/ l
Sal
O
S
pH
2
mV
Store
AR
1
LoBat
nLF
Lin
Oxi
Tref25
Tref20
ARng
8
Time
Year
Ident
No.
Day.Month
Baud
Sal
cm
1/
K
/
%
RCL
REL2
pH
/
mV
m
cm
S/
%
mg/ l
Sal
O
S
pH
C
2 4 8
T 3
°
C
TP
REL1
Cal
TEC
Auto