Ox sender actual function

[Mark Wilcutts]

OK, I scanned the first two pages of the paper, if you're interested
they're on my web site at:
http://vehicle.me.berkeley.edu/~markw/efi/920289.html

I'm not an expert at scanning, and the pages require hand editing, so any
additional pages may require quite some time. If you're interested in the
paper I'd suggest ordering it from the SAE or finding an engineering
school near you to photocopy it. 

(I hope the SAE doesn't kick my ass for copyright violation...)
-- 
Mark

On Wed, 11 Nov 1998, Mark Wilcutts wrote:

> I did a little digging and found the paper, it's SAE 920289 "Operating
> Characteristics of Zirconia Galvanic Cells (Lambda Sensors) in Automotive
> Closed-Loop Emission Control Systems" by Bozek, Evans, Tyree, Zerafa of
> the EPA. I'll be taking a close look at this paper in the next few days.
> 

> On Mon, 9 Nov 1998, Gregory A. Parmer wrote:
> 
> > > However, I believe here I once not to long ago heard someone mention that an
> > > Oxygen sender in fact does not sense Oxygen as that would require higher
> > > heat than present in most exhausts. That actually the sender senses carbon
> > > particulate mater. What are the facts...
> > 
> > Apparently it senses CO and H.
> > The following is taken from my beginnings of a FAQ that never got
> > finished...it was posted by Dale Ulan on 28 Oct 94, I think.  This 
> > version may be edited/abbreviated but a search of the archives will 
> > get you the original post(s).  If you do the research and find the
> > number of the mentioned SAE paper please let me know.  Isn't Dale 
> > still here himself?
> > -greg
> > PS--the faq I started is at
> > http://www.acesag.auburn.edu/~gparmer/efi/myfaq.html
> > There are a few other O2 references also.
> > 
> > ------------------------------------------------------
> > 
> > About 1990, a few people from the EPA wrote an SAE paper on the subject of
> > oxygen sensors. My copy of the paper is at school, so
> >      I can't quote the names or give you the SAE paper number. But I can
> > summarize it, because I was suprised, too.
> >      The EPA was going to do a study of oxygen sensor aging and break-in
> > periods, and quantify how this affects exhaust emissions. They
> >      built a test setup with a heater (which would heat up the sensor and
> > the gas it was exposed to), and a valving system that would allow
> >      them to purge the test system with nitrogen gas, and then give
> > samples of other gasses.
> >      The most obvious test is to see what temperature was required for the
> > sensor to sense oxygen. So they cranked up the O2 flow, and
> >      started heating. The O2 sensor started to respond at about 800 or 900
> > degrees C. No exhaust system operates at that under normal
> >      road-load conditions.
> >      At this point, they decided that their study should concentrate on
> > this lack of O2 sensor activity. What they discovered was that the O2
> >      sensor would respond to carbon monoxide and hydrogen. At normal
> > operating temperatures, they concluded that the O2 sensor is not
> >      capable of sensing oxygen at all. Few people seem to have read this
> > paper, though, so most people out there think that the oxygen
> >      sensor actually senses oxygen in a vehicle. It *can* sense oxygen,
> > but it'll have to be glowing pretty bright to do it.
> >      I would suggest going to your local technical library and finding
> > this SAE article. It will be in one of the annual article abstract books,
> >      somewhere between 1989 and 1993, and may be present in either the big
> > thick SAE publication hardcovers, and/or in 'Sensors and
> >      Actuators', an SAE special publication series (ref Dale Ulan --
> > DIY_EFI email on 28 Oct 94). The output from an O2 sensor is shown
> >      at http://www.bracken.co.uk/misc/ you will see a figure relating %
> > O2, CO, H2, NOx etc to Lambda (ref Gus Cameron -- DIY_EFI
> >      email on 24 Apr 1998).
> > 
> > 
> 
> 
> 
> 
>