CHEAP Carbon Monoxide tester for hut

[TenE307]

I was talking to a pilot buddy of mine about the Mr. Buddy heaters having problems in high altitudes because of their oxygen sensors. That is why I got the sunflower heater. He told me about a sensor they use in airplanes that are cheap and work good. They do have a shelf life once opened. Here is the link: http://www.sportys.com/source/features/search/search.cfm?catalog=PilotShop&keywords=carbon+monoxide+detector

Hope everyone stays safe out there!!!