84
8024250/18HT/V2-0/2020-12| SICK
O P E R A T I N G I N S T R U C T I O N S | ZIRKOR200 Ex-G
Subject to change without notice
11
TROUBLESHOOTING
11.4
O
2
display on 0%, although the operating mode indicates a higher O
2
value
Possible cause
Notes
Measuring probe heater defective
(resistance must be approx.
37.5...47.5 Ohm; disconnect on the
analyzer unit and check) Attention:
Disconnect the analyzer unit from the
power supply beforehand
Query the measuring cell temperature (setpoint 800 °C or
840 °C depending on the setting).
A cell temperature lower than 800 °C or 840 °C can cause
a display of 0%.
Thermoelement defective (check
resistance, approx. 2...80 Ohm)
Replace the inner part of the measuring probe.
Fuse of the heating voltage defective
Replace the fuse.
Transformer (230/115 V) defective
Check voltages.
Line short-circuit
Electronics inlet defective
Wire break
– Check wiring.
– Measure the connection cable
mV-tap in the analyzer unit (measuring
signal wire) is not available or
interrupted
Check the inner part of the measuring probe for good
contact.
Combustible components in flue gas
Check that the analyzer unit reacts to test gas. When the
analyzer unit reacts to test gas, there may be a higher
percentage of combustible gases in the flue gas. In this
case, reducing conditions prevail on the O
2
measuring cell,
which reduce the O
2
content on the cell surface.
Measuring cell defective
Replace the measuring cell.
