O2 sensor question

[Mike (Perth, Western Australia)]

At 12:46 PM 23/3/2000 -0800, garwillis at msn.com (Garfield Willis) wrote:

>>Are there any specs for the sensor ?
>>
>>I'd like to integrate the display into my own equipment,
>>
>>Tah
>
>Hey, one thing I gotta know...what's this "tah" interjection you often
>use, mean in WestOz? Is it like a grin, or a "heh heh" or "hee hee" like
>we do in the States? I've never seen it before and kinda appreciate the
>general Aussie verbal style, so I had to ask. If it's difficult (or
>embarrassing) to convey via public typing, don't sweat it.

hehe - LOL :)

Well its mostly an English slang for a friendly  "Thanks", seems to have
been adopted generally in Oz, given our large intake of Poms (English
immigrants). Generally when you've lived here for a while one tends to
get casual about communications - not just on email, most ozzies don't
stand too much on ceremony or protocol (except when the queen visits;)
[The real sweaty stuff I leave for my GF ;-]


>Anyway, on to your question. This has been explained before, but this
>type of sensor (the Honda-NTK sensor is one of the so-called
>"current-pump" types) REQUIRES a special sort of interface electrics to
>go with it. It's not merely a passive sensor like the older "Nernst" or
>switch type sensors, which just put out a voltage you read. There's a
>little pump inside these new sensors that squirts oxygen ions into (or
>out of) another measurement cell, in an attempt to balance out excess or
>depletion of oxygen in the exhaust gas. This clever trick is what allows
>these sensors to be so "linear" and good as O2 measurement devices, but
>makes operating the sensor more complicated than the older type.

Where does the platinum type Bosch O2 sensor come into this, is that the
Nernst type you mention ?

>EGOR *is* that special interface electrics. If you want to roll your own
>display, you could use just an EGOR-module, and build your own
>instrument around that, but when you see how snarky and inexpensive our
>EGOR-meter is going to be, you'll probly just go for that instead.

mmm OK - interesting - please update me as soon as you can on your product,
:)


>This discussion allows me to add another comment/recommendation about
>how to plan for using these sensors. Ya know, they're all still pretty
>spendy, even with the Honda sensor available with a goodly discount over
>the net for slightly less than $100, that's still a pretty decent
>chunkOchange for "consumables". I would think twice about planning on
>having such a sensor left in the exhaust ALL the time, and part of your
>normal everyday panel meters. Everybody knows that rich running, oil
>burning, and lead mix all contribute to shorter lifetimes for these
>sensors. Add to that the fact that any heated sensor has a VERY hot
>ceramic bit in them that can be instantly fractured if clobbered by a
>errant drop of water from a cold exhaust system. All it takes is
>condensation in the wrong place, a (perhaps unbeknownst to you) poorly
>chosen placement of the O2 bung, and all these things may put you in the
>position of test engineer where the supplies of sensors is paid for out
>of your own pocket. The auto mfgs. found out about those types of
>mistakes and paid for them (usually, hopefully) during engineering
>trials. You might want to avoid those costs if possible.

mmmm - I'd like to know where I could buy a sensor off the net, our local
parts dealers seem to add about 300% markup (on anything) and then another
100% if its anything technical or elctronic :(

>Sure, you're gonna go for it if you're planning on a WOT/wideband ECU,
>because you don't have any choice, and you need that WOT tight control
>to get your track times down, or whatever. But if you're using it for
>tuning and tweaking your open-loop fuel maps in your EFI controller from
>time to time, I'd suggest you consider it a hand-held instrument that
>you use via a tail-pipe probe, and you only expose the sensor to these
>attendant dangers whenever you need to be performing those kinds of
>measurements. On the front panel of the EGOR-meter right below the ON
>switch, you're gonna see a litany of cautions (like a pilot's checklist,
>if you will) to help you avoid damaging the sensor, just because the
>bloody things still cost $100, and in most places that can still buy a
>nice dinner for two. But of course, it's everyone's choice. I'm just
>trying to point out some realities of the situation. Everything possible
>has been done to keep the deployment of this cool measurement technology
>as absolutely low-cost as possible. So the clients we're targeting we
>just ASSUME will want to be very careful with their sensors and baby
>them. But if your gameplan (e.g., WOT controller) or robust pocket
>change allows it, sure go for a permanent wideband sensor in your
>exhaust full-time, and use an EGOR-module to interface that sensor to
>your own custom electrics. That is one of the uses it's intended for,
>except we think mostly for both economy and appreciating the finer
>things in life, if you're not building an engine manager, you'll
>probably find our meter irresistible. :)  But like I said before, both
>the module and meter are going to be very affordable, so the choice will
>be yours.

Ok thats for that - interesting, I suppose it would be almost as good
and cheaper to go for two conventional sensors. One before and one
after the cat and do a bit of maths,

Tah,

Toodle loo

cyah

:) mike

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