Instruction Manual
760000-C
November 2002
3-22 Operation Rosemount Analytical Inc. A Division of Emerson Process Management
Model NGA2000 CLD
CLD
7.50 ppm
HOME
-- Calibration Parameters --
Calibration adjustment limits: Enabled
Calibration averaging time: 5 s
Calibration failure alarm: No
Cal failure error allowed: 50 %
Calibration time out: 60 s
Zero ranges: TOGETHER
Span ranges: SEPARATELY
INFO
ESCAPE
The “Calibration…” submenu provides
quick access to the Expert Controls Cali-
bration menu, Section 3-8c, page 3-23.
Calibration Parameters
This menu provides various parameter
settings for all calibration performed from
Basic or Expert modes.
Main Menu
↓
Analyzer and I/O expert controls &
setup…
↓
Analyzer module setup…
↓
Calibration parameters…
Figure 3-32. Calibration Parameters
Display
Calibration adjustment limits:
Set to “Disable” to recover from a calibra-
tion failure.
Calibration averaging time
:
Sets the time used by the analyzer to av-
erage its reading during calibration. A
longer time will give a better calibration.
Calibration failure alarm
:
When turned on (Yes), issues a warning if
the analyzer has to change its calibration
by more than the Cal Failure Error, if
warning alarms are enabled.
Cal failure error allowed
:
The percentage by which the calibration
can change before an alarm is triggered if
the Calibration Failure Alarm is enabled.
Calibration time out:
Sets how long the analyzer will wait for
the signal to stabilize before issuing a
Warning.
Zero (Span) ranges:
Used to select whether to calibrate ranges
TOGETHER or SEPARATELY. If to-
gether, zeroing or spanning will go
through each range one by one. If the
change required is too great, it will fail and
send an alarm if warning alarms are en-
abled. In this case, Disable Calibration
Adjustment Limits and try again. First
check that the calibration gases are cor-
rect. If non-zero gases are used, or the
changes are great, zero and span may
have to be repeated a few times.
b. Basic
Controls
Calibration
This method allows the user to input a
span calibration gas value and perform a
zero or span calibration for each of the
four ranges.
In the “Basic Controls” menu, move the
cursor to the “Span gas concentration:”
line and set the correct value for the cali-
bration span gas. The zero gas is as-
sumed to be 0.00 ppm.
Begin flowing the calibration gas (zero or
span) and allow time for the analyzer to
stabilize on the gas.
Press the appropriate ZERO (F3) or
SPAN (F4) softkey to display the calibra-
tion menu as shown below.
The “Calibration status” must be READY
in order to initiate a calibration.
Verify that the desired measurement
range is active. If not, press ESCAPE (F2)
to return to the previous menu and
change the range.
The “Zero (Span) ranges” tag indicates if
the ranges will be calibrated together or
separately. See Section 3-8a, page 3-21
to change this.
