IR brethalyzer types

I was reading about these and was just wondering what type of IR theses things ran on (near, far,..), maybe special IR led's?

would it be possible to get that to output to a tv/monitor?

could webcams do it(capture reflecting IR)?

also would these be the same bands to detect co2 clouds?

This kind?

HowStuffWorks "How Breathalyzers Work"

YES! the Intoxilyzer, that page was very informative and helped me understand spectroscopy better, (I always thought that response was dependent on molecule, as oppose to bond type). which clears alot.

but still leaves a few questions,
1)first the quartz lamp, are these common/cheap, can i get em in LED's, could sunlight be a substitute?

2)the photosensor, is this a generic type since it just reads the filtered light anyway, would any work, could a webcam work?

3)the IR filter- can i get one of theses and what type so i can detect the C-O bond? (maybe i can eliminate this by getting the right IR LED COLOR?)

My main goal is to display CO2 vapor (or concentrations) visually., or as best as i can get.