Reference Manual
748384-C
September 2003
Analyzer Variables
Rosemount Analytical Inc. A Division of Emerson Process Management
2-14
NGA2000 Reference
CAPILLARY
Direction Bidirectional
Binding
None
Type Enumerated
Value range
2.5 cc/Min @ 5 psig; 10.0 cc/min @ 5 psig; 13.5 cc/Min @ 55 psig; 55.0 cc/min @ 5
psig; 13.5 cc/min @ 3 psig; 9.7 mL/min @ 3.5 psig (HFID)
Units hPa
Description
FID only; capillary flow rate installed.
Usage
Describes the type of capillary installed. This should match the capillary, of course. It
is used to determine the gain settings on each range, together with CAL_PRESS,
CARBON_ATOMS, FUEL_TYPE and the fullscale ranges.
See also
CARBON_ATOMS
Direction Bidirectional
Binding
None
Type Floating
point
Value range
1 – 8
Units None
Description
FID only; gas response factor..
Usage
Used to determine the response of the analyzer to the calibration gas. FIDs
essentially count the number of carbon atoms in the flame, and thus have a greater
response to higher molecular weight hydrocarbons. The analyzer may be calibrated
on a particular gas specie, and this variable must be set so as to avoid saturating the
analog electronics if higher levels of high molecular weight gases are selected. For
propane, the response factor is about 3.14, for methane it is 1.0.
See also
CAL_PRESS
FUEL_TYPE
CASE_BIAS
Direction Bidirectional
Binding
None
Type Floating
point
Value range
50
Units
°
C
Description
FID only; bias temperature for the case temperature control algorithm.
Usage
Used in the case temperature control PID algorithm. This value should not be
adjusted. CASE_IGAIN
See also
CASE_PGAIN
CASE_SETP
CASE_IGAIN
Direction Bidirectional
Binding
None
Type Floating
point
Value range
0.003
Units None
Description
FID only; the integral "gain" for the temperature control algorithm.
Usage
Used in the control algorithm. This value has been experimentally determined, and
should not under any circumstances be changed.
See also
CASE_BIAS
CASE_PGAIN
CASE_SETP