Single Point Calibration - Mettler Toledo InPro 6800 Serie Bedienungsanleitung

InPro 6800 O
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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 func-
tion SW-700-011 «high CO
ask your local METTLER TOLEDO distributor.
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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 equi-
librium with the air. Oxygen exchange between
water and air is only very slow. Therefore it takes
quite long time until water is saturated with atmo-
spheric 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 steriliza-
tion, the use of an existing membrane body that
has been pre-sterilized while mounted in the sen-
sor 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 steriliza-
tion process.
– Make sure that all other parameters, such as tem-
perature and pressure, are constant.
For continuous applications, we recommend periodic
recalibration in line with your requirements on accu-
racy, the type of process in operation and your own
experience. The frequency of the need for recalibra-
tion 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 calibra-
tion medium can be water with known oxygen satura-
tion 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
measuring system can then be calibrated to the100 %
value of the desired measurable variable, e.g.100 % air,
© 02 / 2023 METTLER TOLEDO
Printed in Switzerland
Sensor 12/25 mm
2
compensation». Please
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52 200 953 C
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InPro 6800