Mettler Toledo InPro6900 Bedienungsanleitung Seite 18

18
Third step: Perform calibration according to the
transmitter' instruction manual.
Fourth step: Adjust the transmitter polarization voltage
back to – 500 mV.
Steps 1 to 4 can be accomplished automatically if you
use the M 700 transmitter. Thus the routine can be
minimized to a few keystrokes. In addition the M 700
transmitter must be equipped with the software function
SW-700-011 «high CO
your local Mettler-Toledo distributor.
General remarks:
– For calibration in air, the sensor membrane must
be dry, since adhering water drops can falsify the
measured oxygen value.
– Make sure that the oxygen saturation index of the
calibration medium is correct and remains
constant during calibration.
– In the event of calibration in water or sample
medium, the calibration medium must be in
equilibrium with the air. Oxygen exchange
between water and air is only very slow. Therefore
it takes quite long time until water is saturated with
atmospheric oxygen.
– For correct calibration, a minimum flow rate of the
calibration medium is necessary.
– Calibration in a fermenter should be performed
after sterilization (as sterilization may alter the
sensor slope), but prior to innoculation. If it is not
possible to perform the calibration after sterilization,
the use of an existing membrane body that has
been pre-sterilized while mounted in the sensor is
recommended. A slope alteration of some per cent
can occur with new membrane bodies, particularly
after a first sterilization, as the tension of the
membrane may be altered by the sterilization
process.
– Make sure that all other parameters, such as
temperature and pressure, are constant.
For continuous applications, we recommend periodic
recalibration in line with your requirements on
accuracy, the type of process in operation and your
own experience. The frequency of the need for re-
calibration depends very much on the specific
application, and therefore appropriate intervals cannot
be exactly defined here.
InPro 6900
52 201 029
InPro 6900 Series O
compensation». Please ask
2
© 12 / 15 Mettler-Toledo GmbH
Sensor 12 mm
2
Printed in Switzerland