Emerson Rosemount Xstream Series Instruction Manual page 169

Instruction Manual
HASAxE-IM-HS
05/2006
Calibration gases..
Tol.Check:
Purge time:
Interval time..
Emerson Process Management GmbH & Co. OHG
6-2 Checking the Instrument's Setup
Off
15 s
Press the LEFT key to return to the CALIBRA-
TION setup menu and concentrate on the "Tol.
Check" entry.
By default the option "Tol. Check" (tolerance
check) is disabled (OFF).
With tolerance check enabled (ON) during
calibration the analyzer checks that the ente-
red (setpoint) values for zero gas and span gas
are reasonable compared to the currently
connected gas. If the currently connected gas
concentration differs more than 10 % of measu-
ring range from zero (during zero calibration)
or span (during span calibration), calibration
is aborted.
This helps avoiding calibrating with a wrong gas
applied (e.g. starting a span calibration while
zero gas is flowing) resulting in an instrument
out of tune.
Note!
The next two lines (purge time & interval time)
show up only if the valve option is other than
None (see installed options menu).
"Purge time": Before starting a calibration it
must be verified that the gas path has been
sufficiently flown through by the calibration gas
and does not contain other components.
In case the gas flow is controlled by internal or
external valves, these valves immediatley apply
the required gas when a calibration starts. Due
to the limited flow and the distance between
valves and measuring cell it takes some time
to fill the cell with the calibration gas. This time
is the purge time, giving a delay in time for
starting the calibration calculations.
Enter a purge time that assures the measuring
cell is sufficiently filled after switching from one
to the other gas.
X-STREAM
6-5