Wide Ratio O2 Sensor

[Thor Johnson]

Not a reply as such, but an idea to use the O2 sensor as a EGT sensor (&
compensate for its infernal resistance going nuts if you need to).  This
should work for both Wide Range and normal EGOs:

Measure the voltage of the EGO w/ a >1M meter, then short it to ground thru
a 120 ohm (or any other known resistor around the internal resistance you
want), and measure it again.

Calling V1 the OC voltage, V2 the shorted voltage, and R the resistor, the
internal resistance of the Ego is

   Rego = R*(V1 - V2)/V2

You could probably do this with a MOSFet tied to a computer output.  It
would take the reading, short w/ the MOSfet, take the second reading, then
calculate what the temp is using the computed Rego.

Question tho':  Why do I care much about the Rego if I use a 10M input?  Do
you
need to correct for temperature on the Wide Range Egos to accound for the
diffusion rates?

-Tj
(Fervently hoping I didn't screw up the Norton equation above)