Hey everyone, thanks so much for your advice and input.

This sounds to good to be true if I understand you correctly. Aaron, is this a controler? One that would be used instead of a timer. Will it shut off the co2 at the desired level? Or is it solely a meter. I thought the controlers were about $600. That's a lot different than the $40 you mention. If this can shut off the co2 at a certain ppm I will take back my $140 cyclestat timer. It mentions programing it using PC based software. Is this hard to do? Have you done it? Can I just say "shut off my generator at 1500 ppm"? This would be wonderful, and much cheaper than the timer. I only found one ebay add about this and it doesn't mention a cable to change the set point. And what cable do I need to attach it to my generator?

From ebay:
New in Box Telaire Vaporstat 8001-N CO2 Ventilation Controller.
All Ventostat Controls are provided with dual analog outputs (0-10 V and 4-20 mA), mounting/wiring sub-base. All 8000 series have a DPST relay (normally open or closed) and can be custom programmed to a specific measurement and output range using the UIP PC based software.
http://cgi.ebay.com/New-Telaire-Vent...QQcmdZViewItem

And does anyone know where I can buy a co2 monitor/alarm? There are many co alarms to choose frorm, but none for co2
that I could find.