Technical Question about O2 Sensors?

[hamish]

On a standard O2 gauge/sensor combo is the sensor comparing atmospheric Oxygen content to what is in the Exhaust gas?

And if so what % O2 indicates a stoichiometric burn?
I had assumed 0%
But that could never work as it would never read a rich mixture.

What %O2 ranges would I need to check the calibration on an O2 sensor?
I am looking to prove the sensor in the range of 11.5-14.7 Air/Fuel Ratio

I am confused with how a gauge/controller and sensor setup (aftermarket) that can only measure Oxygen make the fuel comparison.

I think I understand how the cars computer system can,but a stand alone single process measurement of a O2 gauge should not.

How does it infer the Air/Fuel ratio?
There must be a known table for what %O2 is left over in a less than perfect gasoline combustion process

I ask because I would like to test the accuracy of a O2 gauge I just received.
I have various calibration gasses with varying O2 levels and I have no knowledge on what O2% would be needed to prove accuracy air/fuel ratio.

Can someone lead me in the right direction please.

 

[recordbreaker5]

i read like 10 questions in there and still don't really know what you're asking?!?!?!

 

[hamish]

I butchered it as I edited.
What I want to know is:
what concentration of O2 gas can I apply to the sensor to replicate 11.5:1 to lets say 15:1 Air/fuel ratio.
Straight Calibration gas, what percentages of O2 will let me span the usable range of the sensor?
I have a good grasp on the operation of the sensor now.