the carbon monoxide indicator thing...

[DKirkpatrick]

Hello. Two experienced pilots got very mysteriously killed here in Arkansas about a month ago. Good airplane, two good pilots. I've never used one of those panel mount cards that is supposed to indicate high carbon monoxide.
Question is, are these good, reliable, the best indicator? This problem can sneak up on you, especially in cold weather flying of course.
Would like some best practices type comment.
thanks
dan

 

[PeterNSteinmetz]

At less that 25-30 ppm you’re not likely to see any noticeable effects, looking at CO absorption.

I believe anything under 70 is usually considered safe for fairly long exposure.

In my 69 Cardinal, I see 16-20 with the vents closed up. Drops close to zero when I turn on the cabin heat. Not at all what I expected given that I was checking for leaks from the muffler.

 

[PeterNSteinmetz]

Take it for what it's worth, but this reference claims OSHA has a 50 ppm limit over 8 hours
https://gaslab.com/blogs/articles/c...personal exposure limit,an 8-hour time period.

Thanks, that is a good chart of the various limits. Looks like 70 ppm is the 1-4 hour limit.