Cheap O2 Sensors and reference air

[xxalexx at ix.netcom.com]

> Ok, I'll bite. Could someone please explain to me how the reference air
> for an O2 sensor is inside the wire or comes from the wire? I had kind
> of figured there was an active layer (or layers), with thin conductive
> film electrodes on each side, which still allowed O2 to pass through,
> with the wires attached to the thin-film electrodes.

There is a molecular diffusion transport mechanism involved.
The wires could release O2 at the boundary layer, from various
diassociation energies, such as cosmic rays or high temp, depending
on impurites and  mislocations but the amount would be small.
alex