Ox sender actual function

goflo at pacbell.net goflo at pacbell.net
Wed Nov 25 15:30:12 GMT 1998


Me too.

Jack

Bruce Plecan wrote:

> Sure, I'd like to see it.
> Bruce

> >I found an interesting paper that came out the following year by some Ford
> >people. It is SAE #930352 "Static Characteristics of ZrO2 Exhaust Gas
> >Oxygen Sensors". It sort of rebuts a few of the claims of the EPA paper
> >and presents a ton more data and references. If there's any interest, I
> >can scan and post a few pages.
> >
> >
> >On Tue, 17 Nov 1998, Mark Wilcutts wrote:
> >
> >> 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).
> >> > >
> >> > >
> >> >
> >> >
> >> >
> >> >
> >> >
> >>
> >>
> >>
> >




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