Introduction & O2 Sensor Questions

[Tom Cloud]

yeah, they're on all your posts ...

>Sorry about the attachment, but I have no idea how it got there!  I hope it doesn't show up all the time.
>
>Tom Cloud wrote
>>Jim, you're sending those undecipherable attachments with
>>your e-mail (see bottom)
>
> 
>
>>you'd need some feedback -- a thermistor or such and then a
>>control circuit for the heater.  If the mfgrs would use a PTC
>>thermistor (probably can't make one that'd stand the heat)
>>or use a ferrite's Curie point a-la the Weller soldering iron
>>temperature control elements -- but now we're just wishing.
>
> Actually, I am working on a temperature compensated oxygen sensor for fuel/air measurement in the rich region.  Getting the oxygen sensor with a built in thermocouple has been the most difficult part.  I am curious why you didn't suggest a thermocouple for temperature measurement?  It seems the best method to me, but I've been wrong many times before:-).

I thought I did mention a thermocouple, but after reading
the above, I see I screwed up several ways.  A PTC thermistor
or ferro-magnetic controller are both self-contained
temperature regulators and wouldn't require any external
controller -- unless you wanted more precise control than
they afford.  The thermocouple obviously requires external
signal conditioning and then a controller for the heater.

It is my understanding that EGO sensors are more "accurate"
(i.e. better defined) at known temperatures, but are they
accurate enough to warrant the hassle of either measuring
or regulating the temperature ??

Tom Cloud <cloud at peaches.ph.utexas.edu>