108
EL3000
CONTINUOUS GAS ANALYZERS | CI/EL3000-EN REV. C
… 6 Commissioning
Failure of instrument air supply
It must be ensured that the gas supply to the analyzer module is
shut off if the instrument air supply fails.
This is generally ensured by the installation of a pneumatic shut-
off valve in the combustion gas supply line (refer to
valve in the combustion gas supply line
must be controlled by the instrument air supply in such a way
that, should it fail (and therefore, also in the event of failure of
the continuous purging of the housing) the combustion gas
supply is automatically shut off (refer to
If such a pneumatic shut-off valve is not installed, the following
precautions and measures must be taken:
• The Overall Status or the "Failure" status of the gas
analyzer must be monitored.
• If the status appears, the cause must be verified in the
gas analyzer on site:
– if the gas analyzer is not in operation (for example as
a result of a voltage failure), the operating gases must
be shut off.
– If the gas analyzer is in operation, an adequate
instrument air supply must be verified. If this is the
case, the status messages must be verified. If this is
not the case, proceed as follows:
1. Shut off the combustion gas supply.
2. Restore the instrument air supply.
3. Purge gas analyzer for 20 minutes.
4. Turn on combustion gas supply.
5. Gas analyzer starts automatically.
Note for measuring combustion gases
When measuring combustion gases, it must be made sure that in
case of a failure of the instrument air supply or of the analyzer
module itself the sample gas supply to the analyzer module is
shut off and the sample gas path is purged with nitrogen.
