Emerson Rosemount Xstream Series Instruction Manual page 203

Instruction Manual
HASAxE-IM-HS
05/2006
Gasflow
Procedure
Time
Gasflow
Procedure
Time
Gasflow
CO2.1
Procedure
Time
Emerson Process Management GmbH & Co. OHG
7-3-3 Advanced Calibration
V4
Purging
10 s
V4
Zero 1
29 s
Sample
0.000 ppm
Purging
10 s
The first screen appearing shows that valve V4
is open. Currently the system is purged
(prepurge) to ensure it is properly filled with
span gas when span calculation is started. The
remaining purge time is 10 seconds
(decreasing from the value entered in the
calibration setup screen, see page 7-6).
When the prepurge time has elapsed, the
instrument starts to calculate the zero point
(here indicated by the procedure term Zero 1):
Zero gas is still applied, the time count down
starts at a value corresponding to 2 times "t
for- calibration" (2 x 15 s).
Note!
At dual channel instruments zero spanning
both channels at a time, the procedure line
shows "Zero 1" while calibration is ongoing.
When calibration has finished, for a short
periode (about 1 to 2 seconds) the line shows
"Zero 2" to indicate the second channel has
been calibrated, too.
After zero calibration has finished, the instru-
ment closes the zero gas valve and opens the
sample gas valve. Now a postpurge procedure
starts to indicate that proper sample gas mea-
surement values require the system to be filled
with the related gas only. Postpurge time again
is the purge time entered in the calibration
setup screen (see page 7-6).
X-STREAM
-
90
7-19