Instruction Manual
760000-C
November 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Operation 3-17
Model NGA2000 CLD
CLD
7.50 ppm
HOME
Response time/delay Parameters
Range 1 t90 time: 3.0 s
Range 2 t90 time: 3.0 s
Range 3 t90 time: 3.0 s
Range 4 t90 time: 3.0 s
LON update time: 10 per sec
Output delay time: 0.0 s
ESCAPE
CLD
7.50 ppm
Measure
-- Automatic Range Control --
Actual switch levels…
Switch level hysteresis: 20 %
Usage of range –1: Enabled
Usage of range –2: Enabled
Usage of range –3: Enabled
Usage of range –4: Enabled
Automatic range change control: Enabled
Absolute range upper limit: 10000 ppm
Absolute range lower limit: 10.0 ppm
Back…
CAUTION
.
Make sure that the corrections are not
excessive. If the correction is too ex-
cessive, the calibration routine will fail
and calibration of the analyzer will not
be possible.
f. Response
Time
The response time menus allows the set-
ting of the primary analyzer variable t90
times, the LON update rate and the output
delay time.
Main Menu
↓
Analyzer and I/O expert controls &
setup…
↓
Analyzer module setup…
↓
Gas measurement parameters…
↓
Response time/delay parameters…
Figure 3-23. Response time/delay
Parameters
The
t90 time
adjusts the filtering or damp-
ing factor for the concentration outputs for
each range. They are adjustable from 0.1
to 30 seconds with a default of 3.0 sec-
onds.
The
LON Update Rate
is the rate at
which the analyzer communicates over
the system network. It is adjustable to
“ASAP” (the fastest rate that the network
communicates), “10 per sec,” and “1 per
sec.”
The
Output Delay Time
establishes the
delay for the DIO and analog outputs to
respond to a change in concentration
value. It is adjustable from 0.0 to 30.0
seconds.
To change a value, move the cursor to
the desired line and press the
↵
softkey.
Change the value using the
↑
and
↓
soft-
keys and then press the
↵
softkey again
to save the selection. Press the Back (F2)
softkey before pressing the
↵
softkey to
restore the previous value.
g. Automatic
Range
Change
This menu function allows the setting and
enabling of the automatic range change
for each of the four ranges. The automatic
range switching for increasing values is
effective at the upper range limit of each
range, while for decreasing values it is the
next lower range limit times the hysteresis
percent times the upper range limit.
Main Menu
↓
Analyzer and I/O expert controls &
setup…
↓
Analyzer module setup…
↓
Gas measurement parameters…
↓
Automatic range change parameters…
Figure 3-24. Automatic Range Control
Menu
Set the desired hysteresis level in the
range of 10% to 50% which is applied to
each range transition. (20% is the default
setting.) Enable the desired ranges and
enable the automatic range change con-
trol. To view the actual switching levels,
