by Skippydiesel » Sun Nov 13, 2022 7:12 pm
I use a small digital CO monitor that is designed for use in boat & caravans (travel trailers). From memory it coast about $30 Australian. It is powered by two AA batteries (which seem to last about 2 years). It keeps a running record, so that I can review Max & Min. Has both audio and visual (light) alarm. I haven't put it in my new, yet to fly, Sonex but in my last aircraft I had it located in the passenger foot well, away from vents/drafts, where it should read the highest levels and I can see it (when I don't have a passenger). In about 5 years of use it never alarmed and never recorded levels of any concern.