O2 Volts

[Bruce Plecan]

I *added* heat with the lighter earlier, and no changes were noted.
On the cars being used in really cold temps, the exhaust on several models
the tubing would not crack spit. Meaning while over 210dF, was not really
hot.
On some vettes, the O2s are probably 4' away from the ports.  On a really
cold day, at idle, with mechanics gloves (nomex type)(none operative cat)
you can hold the exhaust back there.
  If the temp was a major concern why is't there a true strategy to
compensate for it?.
  This when hot enough, is this the 800-900dC temp?.  When does an average
engine reach an EGT of that?.
  When speaking of a catalyst, fine, but without knowing what it is, and
what it's properties are, is gets again rather mute, as I see it.
  By the way, in all my testing I was using a strategy where by I know to
some degree what the actual heater temperature is.  So I can duplicate this
on car, and then see what is going on.  Without quessing.
  While oems, are doing this O2 work as a emission law mandated issue, I'm
just trying to figure out enough to do what I want to do.   Other issues
don't matter, other than as a point of interest, or maybe concern for
others.
Grumpy

> >   The useful facts as I see them are:
> >   In cold weather, a none heated O2 sensor can go open loop. due to the
O2
> > sensor being too cold.  A heated O2 develops enough heat so that it can
> > "properly sense" the needed gases to operate.
> >   The O2 sensor, as tested responds to HC rather than O2.
> >   While you might be able to change things, or define other operating
modes,
> > I know that if I mount the sensor far enough away from the engine that
being
> > heated is neseccary, then I know what gases matter, and thus what the
sensor
> > is seeing.

> There are a couple of things I'd like to throw in the mix here.

> The heater on the heated sensor is a helper to get the sensor up to
> temperature... it's probably still relying on hot exhaust gases to
> be at working temperature... it may not be hot enough when testing with
> room temperature gases.

> There is a catalyst on the electrodes which may well promote the
> combustion of gaseous hydrocarbons with the O2 that diffuses thru
> the sensor, hence the reaction to gaseous hydrocarbons.

> The sensor itself, when hot enough senses the relative concentrations
> of O2.  This is not necessarily the O2 concentration in the exhaust
> gases as measured by other means due to the catalytic action of the
> sensor electrode...

> Orin.