Return of the diy_EGOmeter (YES, it's finally ALIVE!!)

[garfield at pilgrimhouse.com]

On Thu, 23 Apr 1998 12:28:51 +0100, Gus Cameron <cameroa at sbu.ac.uk>
wrote:

>Hmm, well, no-one really picked this one up and ran with it.  So.... I took
>a walk across to the library and Lo! Seek and you shall be rewarded etc.
>etc.  
>
>If you check out 
>http://www.bracken.co.uk/misc/
>you will see a figure relating % O2, CO, H2, NOx etc to Lambda.  It helps
>to explain why the outputs from lambda (O2) sensors are non-linear and also
>partially explains the differing curves that Garfield was reporting either
>side of equivalence.
>
>Sorry if this was common knowledge already.

Geez, no apology needed on this end, that's stellar stuff you found
there. Makes me think I might wanna get the book that chart came out of
too! The Horiba box also has a calibration procedure you can follow if
you have known concentration O2 (span/model/sample) gas mix (term you
use apprarently depends on what industry you're working in) with a
prepared concentration (4% is recommended, but you can manually
calibrate the box using anything known, between 0-25%).

And Gus, your conjecture on the shape of the O2 curve in that diagram
explaining the diff. shape on either side of stoich for the sensor IS
dead on target, cuz the shapes of them curves on either side, EXACTLY
mimic what you see in the NTK published 5-wire sensor curves in their
SAE articles. I'd say you've really cleared up a couple of voids in my
understanding from just that one graph. Nice sluething, dude. We oughta
send you out with the black bag more often. B)

Gar