Single Point Calibration - Mettler Toledo InPro 6800 Serie Instructions D'utilisation

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InPro 6800 Series O Sensor 12/25 mm
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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 mem-
brane 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.

5.2.3 Single point calibration

By carrying out a single point calibration, the factual
slope of the sensor can be established. The calibration
medium can be water with known oxygen saturation
index (e.g. air-saturated water) or air with known
water-vapor saturation (e.g. water-vapor saturated
air).
After the sensor signal has stabilized, the complete
meas uring system can then be calibrated to the 100 %
value of the desired measurable variable, e.g.100 %
© 02 / 17 Mettler-Toledo GmbH
Printed in Switzerland
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compensation". Please ask
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InPro 6800
52 200 953