Setting mixture - CO vs Air/Fuel metering?

[twistedtree]

I want to check the mixture on my cars across their operating range.  To do it properly I need to be able to measure mixture at various speeds and loads, and I'm interested in understanding the tradeoffs between using a CO meter and using an air/fuel mixture meter.  There was a great article on the subject in Pagoda Notes Vol 4, Issue 1 doing this with an air/fuel mixture meter.  But CO meters are also effective, it would seem?

If you were going to invest in one of the two, which would it be and why?

[Cees Klumper]

I have a good basic (Gunson) CO meter that I use to set idle mixture level. But I don't think it is useable to set mixtures under load. Must admit I don't recall the Pagoda Notes article but this is what I know?

[twistedtree]

Yes, my past experience with CO meters (very long ago) was setting idle mixture too.  I haven't kept up with test equipment at all over the intervening 30 years.  My current default will be to get an air/fuel mixture meter because I know it can record data over a run with the car which is key to setting mixture in the various ranges.  But it seems that at least in theory a CO meter should be able to do the same thing, so I want to remain open to that as an alternative.  And perhaps there are other pros and cons as well.  I've just been away from it for too long to know.

[Cees Klumper]

The reason I think the CO meter I have would not do the job is that it requires inserting a probe into the exhaust to measure the mixture. Once you start driving a car, I think the wind turbulence around the exhaust would prevent taking an accurate reading - but I could be wrong, just never really looked into it.