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5 Maintenance
5.1.8.1 Offset Calibration perform to 21 % O
2
Before offset calibration, check whether R
ki
O
2
value is equivalent to 15 (see menu 211 and
213 in chapter 5.1.3 Reading the Measured Values).
Otherwise, proceed as described in chapter 5.1.6 Response of the Internal Resistance Reg-
ulation.
Fig. 5-1 R
ki
Display
Also check the probe voltage U-O
2
. It must be in the range of +10 ... -20 mV.
To perform an offset calibration, the probe must be located in the ambient air and should run
for at least 30 minutes in a fault-free measuring mode.
No access level is required!
NOTICE
When using a LS2-HT (type 656R2015), the offset calibration can also be performed in an in-
stalled state whilst combustion is running. For this purpose, air (dry and oil-free air, instrument
air or ambient air) must be fed at connection with a volume of 40 ... 60 l/h for the duration of
the calibration.
Activate MAINTENANCE MODE!
select the probe for Calibration in the main
menu .
Select for the offset calibration.