Single Point Calibration (Slope Or Process Calibration); Slope Calibration (Inpro 6870 I, Inpro 6880 I And Inpro 6960 I); Process Calibration - Mettler Toledo InPro 6000 Serie Instructions D'utilisation

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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.
5.3.3 Single point calibration (Slope or Process Calibra-
tion)
For most applications, a single point calibration should
be sufficient, as long as not the whole measuring range
of the sensor is used.
By carrying out a single point calibration, the factual
phase at the desired oxygen value e.g. at hundred per-
cent oxygen (phi 100) of the sensor can be established.
The corresponding calibration curve is calculated.
5.3.4 Slope calibration (InPro 6870 i, InPro 6880 i and
InPro 6960 i)
For most applications where oxygen levels between
10 % and 200 % Air saturation are measured a single
point slope calibration is sufficient to reach the re-
quired accuracy.
The calibration medium can be either air or a calibra-
tion gas with known O
known oxygen concentration.
Before starting the calibration in gas, the correct pres-
sure and the correct humidity have to be set in the
transmitter.
Note: Wrong pressure values are the most common
reasons for bad measurement accuracy.
E.g. 50 mbar difference between the ambient pressure
and the value set in the transmitter result in 5% mea-
surement error at air.
For calibration in gas it is important that the tempera-
ture reading of the sensor is stable and represents the
real gas temperature.
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 %
air, 20.95 % O
normal pressure (see instruction manual for the
transmitter).

5.3.5 Process calibration

A process calibration is needed in a situation when the
sensor can not be removed from the process.
For detailed information please refer also to the trans-
mitter manual.
Two different routines for process calibration are pos-
sible:
– Process calibration
– Process scaling
InPro 6000 optical O
52 206 256
InPro 6000 Series Optical O
2
, or 8.26 ppm at 25 °C (77 °F) and
2
sensors
2
concentration or water with a
© 08 / 12 Mettler-Toledo AG
Printed in Switzerland
Sensors 12 mm
2