O2 Volts

[rr]

Orin Eman wrote:
> 
>???? wrote:
> >   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.

Yes, this makes sense. I was thinking that there is a very thin
layer of platinum deposited on the sensor cone during manufacturing.
Can't remember where I got the info from.

So, my brains cells didn't fail me...

BobR.

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