Specifications

I
NTRODUCTION
748410-A
August 1999
1
Chemiluminescense Detector Analyzer Module
Rosemount Analytical NGA 2000
1
1.1 O
VERVIEW
This manual describes the Chemiluminescence (CLD) Analyzer Module of Rosemount
Analytical's NGA 2000 Series of gas analysis components (See Figures 1-1 and 1-2).
The CLD Analyzer Module is designed to continuously determine the concentration of nitric
oxide and oxides of nitrogen (NO plus nitrogen dioxide [NO2]) in a flowing gaseous mixture.
The concentration is expressed in parts-per-million.
The CLD Analyzer Module is designed as a slide-in module (if configured in stand-alone
instrument fashion), removable from the front of the Platform, with gas connections made
from the rear. All electronics relative to sample detection and conditioning are included in
this module.
1.2 T
YPICAL
A
PPLICATIONS
The CLD Analyzer Module has specific applications in the following areas:
•
Oxides of nitrogen emissions from the combustion of fossil fuels in:
•
Vehicle engine exhaust
•
Incinerators
•
Boilers
•
Gas appliances
•
Turbine exhaust
Nitric acid plant emissions
De-NOx control system
Nitric oxide emissions from decaying organic material (e.g., landfills).
1.3 T
HEORY OF
T
ECHNOLOGY
The CLD Analyzer Module uses the chemiluminescence method of detection. This
technology is based on NO's reaction with ozone (O
3
) to produce NO
2
and oxygen (O
2
).
Some of the NO
2
molecules thus produced are in an electronically excited state ((NO
2
* - the
"*" refers to the excitation)). These revert immediately to the ground state, with emission of
photons (essentially, red light). The reactions involved are: