Instruction Manual
760000-C
November 2002
Rosemount Analytical Inc. A Division of Emerson Process Management Installation 2-3
Model NGA2000 CLD
Figure 2-2. CLD Rear Panel Connections
c. Specifications
Calibration Gases
Either U.S.P. breathing grade air or nitrogen
is recommended for use as zero gas. A mix-
ture of NO or NO
2
in a background of nitro-
gen is recommended as span gas. For
maximum accuracy, the concentration of
NO in the span gas should be about the
same as that in the expected sample
stream.
Ozonator Source Gas
For analyzers with ranges less than
0 to 2,500 ppm, U.S.P. breathing grade air
should be used for generation of the ozone
required for the chemiluminescence reac-
tion. For ranges greater than 0 to 2,500
ppm, breathing grade oxygen is required.
Sample
The sample must be clean and dry before
entering the Analyzer Module. Sample
should be filtered for particulates down to
two microns, and should have a dew point
5
o
C (13
o
F) below coldest ambient tempera-
ture.
WARNING
At no time should sample flow exceed
2200 cc/min. Damage to internal compo-
nents may occur if this flow level is ex-
ceeded.
CAUTION
.
EXTERNALLY RESTRICT SAMPLE FLOW
TO LESS THAN 2200 CC/MIN.
No restrictor is provided in the sample
inlet of this module. For those users
who cannot externally limit sample flow,
accessory restrictor PN 657300 is avail-
able from Rosemount Analytical. To ob-
tain this accessory, call 800-433-6076.
Pressure
Between 690 and 1035 hPa-gauge (10 and
15 psig) of ozonator air (or oxygen, if ap-
propriate) should be present at the rear
panel of the module. Bypass sample gas
flow rate should be between 700 and 2000
cc/min. with backpressure regulator pres-
sure (see Capillary Pressure in “Current
Measurement Parameters” menu, which
can be viewed by selecting the PARMS
softkey in “Main Menu”) adjusted to 344
hPa (5 psig).
EXHAUST
OZONATOR AIR
EXHAUST FAN
SAMPLE IN
INTAKE FAN
