32  AO2000 CONTINUOUS GAS ANALYZERS  |  OI/AO2000-EN REV. B 
 
 
 
Purge gas flow monitoring 
Purge gas flow monitoring 
The purge gas flow is continuously measured by a flow sensor. The signal of 
the flow sensor is monitored and evaluated by a function block application. 
This function block application is configured ex works. The monitoring and 
evaluation is designed individually for each analyzer module. 
Function block application for purge gas flow monitoring 
Detektor-
messwert
‘Flow’
Einh.: l/h
Fan
‘Flow Spuelgas’
Grenzwert-
wächter
‘Flow Spuelgas 1’
Schwellwert: > 50 l
Hysterese: 3 l
Meld.-Nr.: xxxxx
Meldungs-
generator
‘Flow Spuelgas 1
Grenzwert-
wächter
‘Flow Spuelgas 2’
Schwellwert: < 15 l
Hysterese: 3 l
Meld.-Nr.: xxxxx
Meldungs-
generator
‘Flow Spuelgas 2’
Meldungs-
eingang
‘Flow error’
Meld.-Nr.: xxxxx
Negierer
‘Flow error’
Digital-
ausgang
‘Flow error’
DOx
 
Output of a status signal 
In the event of a flow error in the purge gas feed path, a status signal is 
output via a digital output (see "Analyzer data sheet"). The user must con-
nect the status signal so that a visible or audible alarm is triggered.