Line of Gas Sensors for Air Quality Measurement?

I’ve currently working on a Autonomous Blimp and while the idea of having a sweet neat little floating platform is indeed enticing I really want to make it “useful.” I have come up with two possible uses for it: a HAM radio repeater for use in emergencies/natural disasters and a gas sensor to measure ambient air quality(see note 1)

Note 1: A gas sensor, such as piD-TECH® plus Photoionization Sensor that I found by Baseline-MOCON,Inc might be the answer. I’ve never used a gas sensor so I don’t know what make one gas sensor “better” than another but this one seems, at least to me, to be pretty good. I contacted the company and they got back to me in under a day so I think support is pretty good. I would really love for Sparkfun to look into it. If this sensor was made available for a variety of gases, even a specific variety such as CO and other pollutants, I’m sure people would buy it. I know I would :). It would introduce an entire new area for hobbyist. Gas sensors would allow hobbyist to building a number of applications: inteligent smoke/carbon monoxide alarms, air quality sensors, welding support sensors(for sensing leaks and such), etc. I think it would be a great addition to the Sparkfun product line

I don’t have any experience with gas sensors, but Futurlec carries a few of them: http://www.futurlec.com/Gas_Sensors.shtml

Check out http://www.citytech.com/ We have had good luck buying in lowish quantities in the past.