Teledyne T200 Operation Manual page 288

Principles of Operation
140
120
100
80
60
40
20
13.1.3. NO AND NO
X
286
Teledyne API – T200 NO/NO2/NOx Analyzer Operation Manual

Infrared 
Visible
Spectrum
PMT
Response
0
0.5 0.7 0.9
Area of Sensitivity
Figure 13-2:
DETERMINATION
2
The only gas that is actually measured by the T200 is NO. NO
(which is defined here as the sum of NO and NO
gas is not detected because NO
In order to measure the concentration of NO
the T200 periodically switches the sample gas stream so that the pump pulls it through a
special converter cartridge filled with molybdenum (Mo, "moly") chips that are heated
to a temperature of 315°C.
2
3
1
NO/NO
X
VALVE
NO + Mo NO + Mo
2
at 315˚C
MOLYBDENUM
CONVERTER
NO + NO
2
from Sample Gas Inlet
Figure 13-3:
NO + O Emission Spectrum
3
Optical Hi-Pass Filter Performance
1.1 1.3 1.5
Wavelength (micrometers)
T200 Sensitivity Spectrum
does not react with O
2
, and therefore the concentration of NO
2
NO only
AUTOZERO
VALVE
2
To Exhaust
1
Manifold & Pump
3
O
O from
y z
3
O Generator
3
To Exhaust
NO+O
3
PMT
 NO Conversion
NO
2
1.7 1.9
, and therefore NO
2
in the sample gas), contained in the
2
to create chemiluminescence.
3
Manifold
& Pump
06858E DCN7057
x
,
x