284  AO2000 CONTINUOUS GAS ANALYZERS  |  OI/AO2000-EN REV. B 
 
 
 
Combustion gas supply from a central unit 
1  Switch off the gas analyzer power supply. Ensure that the shut-off valve 
in the combustion gas supply line is open. 
2  Set the combustion gas pressure at 1.1 x the normal pressure of the 
combustion gas, i.e. at approx. 1.4 bar. 
3  Mark pressure indication on the gauge of the pressure reducer. 
4  Shut off the combustion gas supply. 
5  Observe the display on the pressure gauge – it should not change 
measurably in 10 minutes.   
A measurable change in the display is an indication of a leak in the 
combustion gas path between the pressure reducer and the combustion 
gas inlet valve of the gas analyzer. In this case the following measures 
are to be taken: 
1  Check the combustion gas line between the pressure reducer and 
gas analyzer with a leak detection spray. A leak in this area must be 
remedied and another leak test must be performed before the gas 
analyzer is put into operation again. 
2  If no leak is found that means the gas analyzer combustion gas inlet 
valve is leaky. In this case, the gas analyzer may not be returned to 
service on any account! The combustion gas inlet valve must be re-
placed by ABB Service. 
6  After conclusion of the seal integrity test, set the combustion gas pres-
sure to normal pressure again, i.e. 1.2 bar.