WB O2 and EGT compensation

[Greg Hermann]

>"While it is true that the UEGO sensors are somewhat
>exhaust gas temperature dependent, this effect can
>be minimized by several techniques, some of which use
>the characteristics of the sensor itself. In fact,
>using an EGT probe to compensate would prove to be
>a less effective solution as the probe would not
>accurately reflect the UEGO sensing element
>temperature. In our wideband controller we have
>employed techniques to reduce the effect of
>temperature-induced error to less than 0.05 AFR with
>an overall accuracy of better than 0.1 AFR.
>Unfortunately, I can't go into detail on exactly how
>this is achieved as this is proprietary information."
>

>So what do you guys think they did? What about their
>claims of accuracy? Do they sound feasible?
>
>Dave


I suspect that, since the resistance of the heater in the sensor varies
with its temperature, that they back read the heater resistance in their
controller, and then correct the output based on this resistance reading.

Why doncha try asking them the same question about the effect of
significant exhaust gas pressure on their reading?? (As in placing the
sensor upstream of a turbo.)

Might make for an interesting answer!

Greg


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