Calibration; Purpose Of Calibration; What You Have To Know For Calibration - Mettler Toledo InPro6900 Bedienungsanleitung

InPro 6900 Series O
Important! To ensure the supply of the correct polari -
za tion voltage the transmitter must be set accordingly.
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.
Please remove the watering cap from the sensor,
rinse the sensor with water and dry it for at least 10
minutes before starting calibration.
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
reading 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 dissolved
oxygen is being measured in standard applications
(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.
© 12 / 15 Mettler-Toledo GmbH
Printed in Switzerland
Sensor 12 mm
2
Where is oxygen
being measured?
Measurement of permanently low oxygen
concentrations (<500ppb) in the pre-
(e.g. CO
sence of volatile acidic components
at measurements in breweries).
2
Follow step 1 to step 4
and general remarks
17
)
2
below.
InPro 6900
52 201 029