Xylem handylab OX 12 - Manual (Page 23)

handylab Ox 12 Operation
23 ba75369e04 01/2011
4.3 Calibrating
Why calibrate? D. O. probes age. This changes the slope of the D. O. probe. Calibration de-
termines the current slope of the probe and stores this value in the instru-
ment.
Thus, you should calibrate at regular intervals.
Calibration
procedures
The handylab OX 12 provides 2 calibration procedures:
z Calibration in water vapor-saturated air.
Use an air calibration vessel for calibration.
z Calibration via a comparison measurement (e. g. Winkler titration accord-
ing to DIN EN 25813 or ISO 5813). At the same time, the relative slope is
adapted to the comparison measurement by a correction factor.
When to calibrate? z After connecting another D. O. probe
z If the sensor symbol flashes, i. e. after the calibration interval has expired
Setting the
calibration interval
The calibration interval (Int 3) is set to 14 days in the factory. You can select
the interval in the range of 1 ... 999 days.
Printing the
calibration
record
The calibration protocol contains the calibration data of the current calibration.
You can transmit the calibration protocol to a printer via the serial interface
(see page 37).
Note
You can automatically print a calibration protocol after the calibration. To do
so, connect a printer to the interface according to section 4.5.3 before cali-
brating. After a valid calibration, the record is printed.
8
LoBat
Time Baud
Day.Month No.
Ident Year
Sal
%
mbar
1 S
RCL AR
Store Auto
Cal
° F
1/cm
/ K %
TDS UpH Sal
mV/pH
S/ m
cm
cm M
Lin
Tref25 Tref20
nLF
AutoCal DIN
AutoCal TEC
6 7 1
9 2 7
O
° C
mg/l
ARng
TP