H2 spectrometry?

[xxalexx at ix.netcom.com]

> 3) H2 concentrations are about 1/2 CO concentrations, at all 
> mixtures.
> 
> CO can be detected using IR spectrometry, but H20 has an 
> overlapping range, so exhaust gas must be dried to get an 
> accurate reading. This is obviously impractical for a view as you 
> drive type guage.  
> 
Modern instrument gradeCO NDIR analyzers are not sensitive to water 
vapor, typically less than 0.1% of FS using a CO2 water bubbler.
They are not designed for watervapor to condense in the cell, this
will create noise of up to +-10% FS
If you have a CO meter that is senstive to water vapor the standard
practice is to use a calcium carbonate desicant, a correction formula
is in 40 CFR 86.
There are also FTIR analyzers in use which can use
software correction for most interference conditions.
I have also tried mass spectrometry but there is a huge CO2 
overlap, so you must use special cryo trapping.  Horibia
just came out with a commercial  MS  system, but I have not reviewed 
it.  For exhaust sample water elimination at least 2 filters or 
needed Balston makes several grades of coaelesing filters for 
automotive use.
> But the question is, is H2 spectrometry doable in this case?
>  
This method was standard practice for many moon's, probably
since 30's? I used a Baily combustable A/F meter untill 77 at Carter
Carb. we then went to 5 gas analysis and in 78 to Horibia A/F meter
for faster response.
The Bailey unit burned 100% H2 gas and has I recall was not very
good  above 14.7.  Handheld portable H2 are widely used in chemistry
industry for flammable gas safety. very sensitive, we could detect
H2 gas from can of soda.  I was looking into the sensors about 10 yrs
ago, the price varies alot, handhelds under $200?, I did remember 
finding just sensor for about $30 somewhere.
alex