Teledyne 200AH 用户手册

 

The Teledyne API Model 200AH Analyzer is designed to measure the concentration of nitric 
oxide [NO], total oxides of nitrogen [NO

x

] and, by calculation, nitrogen dioxide [NO

2

] (Note: the 

calculation of NO

2

 is not available in instruments equipped with the Oxygen measurement 

option.) With the proper setup, it can operate in any of three sampling modes. 

NO/NO

X

 

switching mode 

Converter is switched, measures NO, NO

x

, and NO

2

. 

NO only mode 

Converter is switched out of sample stream. Nitric Oxide is only 
gas measured. 

NO

x

 only mode 

Converter is switched into the sample stream, NO

x

 is only gas 

measured. 

 

Regardless of which sampling mode the instrument is operating in, the signal from the M200AH 
comes from the light emitted from the chemiluminescent gas phase reaction of nitric oxide [NO] 
and ozone [O

3

] as follows: 









 







 

The reaction of NO with ozone results in electronically excited NO

2

 molecules as shown in the 

first equation above. The excited NO

2

 molecules release their excess energy by emitting a 

photon and dropping to a lower energy level as shown in the second equation. It has been shown 
that the light intensity produced is directly proportional to the [NO] concentration present. 

In the NO mode, the sample gas is routed directly into the reaction cell. Any NO gas present 
reacts with ozone, producing light as described above. 

In the NO

X

 mode, the sample gas is routed through a NO

2

 to NO converter, and any NO

2

 present 

is reduced to NO. The NO initially present remains as NO, therefore the signal is the sum of NO 
and NO

2

 present in the sample gas stream. 

In the NO/NO

X

 switching mode the Analyzer samples the gas stream and measures [NO] 

concentration by digitizing the signal from the Analyzer's photomultiplier tube (PMT). The