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: Tuesday, November 17, 1998 10:58 PM
Subject: Re: Ox sender actual function


Doc and I say thanks
Bruce


>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).
>> >
>> >
>>
>>
>>
>>
>>
>