Lambda Sensors....

[tom cloud]

>
>With all the talk on Oxy sensors, I thought I might ask a few more 
>questions (aack! do I *ever* have any answers?):
>
>  The Lambda sensor is good for only a small range... Can it reliably 
>   sense the "Power Band" of a mixture, or is that too rich for it?
>
>  Several people have mentioned temperature instability.  Because this is
>   a "research vehicle" (at least in my mind, 'cuz I know little about 
>   gas engines), I was planning on mounting the lambda sensors approx 1-2"
>   from the exhaust ports (1/cyl to make the microconfuser code easier).  
>   Can I get relaible readings here, or will the exhaust temp cycling 
>   confuse my sensor?

The papers I read show that the EGO output is useable at stoich once
it's above some temp (600 C seems to stick in my mind ??).  It's
off stoich where the variations make the sensor 'inaccurate' but
not necessarily unusable (I love talking in generalities -- I can sound
so knowledgeable without knowing anything -- called 'blowin' smoke').
Serially, though, EGO is used by auto mfgrs for stoich.  Most now
heat it to get it to temp faster.  I wonder if any oem uses it for
any data other than stoich?  (i.e. does anyone do closed loop at any
A:F other than stoich??)  From my experience looking at a digital
readout, you can get an indication of what's going on, but I don't
think I'd want to use that data to close the loop on a confuser.


Tom Cloud <cloud at peaches.ph.utexas.edu>