Calibration; Purpose Of Calibration; What You Have To Know For Calibration - Mettler Toledo InPro 6800 Serie Instructions D'utilisation

18
5.2

Calibration

5.2.1 Purpose of calibration

Each oxygen sensor has its own individual slope and
own individual zero point. Both values are subject to
change, for example, through electrolyte consumption
or after exchange of electrolyte or membrane body. To
ensure high measurement accuracy of the sensor, a
calibration must be carried out after each change of
electrolyte or membrane. Prior to calibration, the
sensor has to be polarized for at least 6 hours.
A zero point calibration is only advisable if very high
accuracy is required at low oxygen concentrations.
To check if your sensor needs a recalibration, you
may dry it and take it in the air to check that the read-
ing is close to 100%. If not, then the sensor needs
a new calibration.

5.2.2 What you have to know for calibration

Attention! If dissolved oxygen is being measured at
low concentrations (<500 ppb) in the presence of
volatile acidic components (e.g. carbon dioxide (CO
measurements in breweries), the calibration procedure
described below should be followed in order to achieve
the best measurement performance.
No special calibration procedure is required if dis-
solved oxygen is being measured in standard applica-
tions (e.g. measurement in biotechnology).
Standard applications
(e.g. measurement in
biotechnology).
No special procedure required.
Refer to transmitter instruction
manual and general remarks below.
First step: Adjust the transmitter polarization voltage
to – 675 mV. Detailed information is given in the trans-
mitter instruction manual.
Second step: After adjusting the polarization voltage
to – 675 mV, equilibration time is required. Wait for
about 5 minutes before carrying out step 3.
Third step: Perform calibration according to the trans-
mitter' instruction manual.
Fourth step: Adjust the transmitter polarization voltage
back to – 500 mV.
InPro 6800
52 200 953
InPro 6800 Series O
Where is oxygen
being measured?
Measurement of permanently low oxygen
concentrations (<500ppb) in the pre-
sence of volatile acidic components
(e.g. CO
2
© 10/05 Mettler-Toledo GmbH
Sensor 12/25 mm
2
at measurements in breweries).
Follow step 1 to step 4
and general remarks
below.
Printed in Switzerland
)
2