Ox sender actual function

[Bruce Plecan]

-----Original Message-----
From: Mark Wilcutts <markw at vehicle.me.berkeley.edu>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Wednesday, November 25, 1998 1:20 AM
Subject: Re: Ox sender actual function

Sure, I'd like to see it.
Bruce


>Just in case ANYONE is still interested in this subject...
>
>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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>