Emerson NGA2000 TO2 Manuel D’Utilisation

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Instruction Manual 
748374-F 
March 2003 
Rosemount Analytical Inc.    A Division of Emerson Process Management 
Startup and Operation           3-3 
Model NGA2000 TO2 
3-3 STARTUP PROCEDURE 
Establish sample or zero gas flow through the 
analyzer module at a nominal flow rate of 2 
SCFH (1 l/min).  Allow gas to flow for 15 to 30 
seconds before applying power. Apply power to 
the TO2 Analyzer Module.   
Upon initial startup, the separate modules, Con-
troller Board and network "self-install." The dis-
play shows the progress of the automatic 
installation routine, together with a button 
marked RE_INIT.  If the initialization hangs up, 
pressing the RE_INIT button will restart it, but 
will cause all the binding information to be 
erased.  The Display will then appear as above.  
For details on binding, please consult the Plat-
form instruction manual.  
Establish that sample flow rate is within specifi-
cations (see Section 1-5 SPECIFICATIONS on 
page 1-4). Input security codes (see NGA Ref-
erence manual), calibrate, and begin routine 
operation as following subsections indicate. 
3-4  QUICK START FEATURE 
This analyzer module is equipped with a quick 
start feature which allows the sensor to begin 
measuring low ppm oxygen faster.  This feature 
can be used when the analyzer is first turned on 
to decrease the time required for the sensor to 
reach equilibrium.  This function is most effec-
tive for gas sample measurements below 100 
ppm.  To maintain sensor life, it is recom-
mended that this feature be used no more than 
two times in any 24 hour period. 
Under the Basic Controls sub-menu, move the 
cursor to Initiate quick start! and press the 
↵ 
key.  The unit will begin the quick start function 
immediately.  This procedure will last for ap-
proximately 45 seconds.  The last measured 
value is held for the duration of the procedure to 
prevent false reading fluctuations. 
3-5  GAS SCALE FACTOR (GSF) 
The Gas Scale Factor is used to correct for 
background gases other than nitrogen.  When 
the background of the sample is other than ni-
trogen, the diffusion rate of oxygen into the sen-
sor changes.  By correcting for the background 
difference, the diffusion change can be com-
pensated in software.  The GSF can be entered 
manually or calculated automatically.  Calcula-
tion of the GSF requires the user to enter the 
sample gas composition.  In most applications, 
the GSF is not required.  However, some back-
grounds exhibit significantly different diffusion 
characteristics versus nitrogen (such as helium 
or hydrogen) and the GSF may improve per-
formance. 
Under the Technical Level Configuration sub-
menu, select  Diagnostic menus...  and then se-
lect Analyzer Module Diagnostics….  In the 
Analyzer Module Diagnostics sub-menu select 
Calibration Parameters....  In the Ad-
vanced/Expert Calibration sub-menu select Gas 
Scale Factor...
. To use the GSF, enter the 
volumetric percentages of each component pre-
sent in the sample gas.  To view more back-
ground components, press the MORE softkey.  
The total must add up to 100 or a new factor will 
not be computed.  If you have a background 
component which is not shown in this menu, 
please consult the factory for assistance. 
Once you have entered all the background 
composition information, move the cursor to 
Compute new adjusted gas scale factor! and 
press the 
↵ key and the analyzer module will 
automatically calculate the new gas scale factor.   
3-6 CALIBRATION 
The TO2 analyzer module is fully factory cali-
brated using certified gas standards prior to 
shipment.  If the analyzer is operated within its 
specified operating conditions, no calibration is 
required.  The zero calibration is very stable and 
does not require checking more than once a 
year.  Depending upon the nature of your appli-
cation, it may be beneficial to verify the span 
calibration of the analyzer module every 3-4 
months.   The following procedure illustrates 
how to initiate a zero/span calibration. 
Under the Expert Controls sub-menu select Ex-
pert Analyzer Controls and Measurement…
, set 
the Range Number to the range that will be 
used during sample analysis.  Return to the 
Main Menu by pressing the HOME softkey.