Fluidplay

How can I find out what the range of voltage for an O2 sensor sends out based on AFR's? Can this be done?

Meaning if there is:

10 AFR's = 0.000v
20 AFR's = 5.000v

I can't find any data on this and the tech sheets from my WB doesn't have this info.

Rogue_Ant

What WB setup are you using? Are you trying to log voltages directly from the sensor, or the V-out from your WBO2 controller?

Fluidplay

using an Autometer listed here, v-out from the gauge to the ecu/controller. http://www.autometer.com/cat_gaugede...id=3604&sid=11

Rogue_Ant

It says it outputs a 0-4volt linear signal for your range... So what is the low AFR and high AFR range?

Fluidplay

mmmm... 0-4v data output feed for ecu / 10:1 to 20:1 AFR range of gauge.

I'm assuming then, just for sake of simple equations, at 10:1 = 0v and at 20:1 = 4v

Rogue_Ant

Yep. So any AFR can be easily calculated:

2.5 x Volt + 10 = AFR


-Rogue

Fluidplay

ok, don't want to sound like a complete idiot, but what does 2.5 & 10 represent in this equation?

minho78

Equation that will give you the range of the AFR relative to the variable volt. So as the variable volt changes you get the specific AFR for that voltage. The 10 is the range you have specified by the manufacturer. Now the 2.5 I'n not sure I think it's the constant that will give you the right values like
2.5X(0v)+10=10AFR
2.5X(1V)+10=12.5AFR
2.5X(4V)+10=20AFR

if you plug the different values from the range(V) and you plot them you get the Voltage and corresponding AFR.

SirLapsalot

Rogue should prolly answer this one but,

your voltage range was 0-4v so 4
your AFR range was 10-20:1 so 10

So your AFR/Voltage ratio is 2.5. so you use this value to multiply your voltage readings by and you have to add 10 because your starting value for the AFR is 10:1.

If you look at the units you have AFR/V * V(reading on meter) + AFR(the 10 units you add) = AFR

Rogue_Ant

These guys have the idea. The 2.5 is the slope of the line, the 10 is the offset.

So, just as they said, take the voltage from the WBO2 multiply by 2.5 then add 10 - that will give you the AFR.

Fluidplay

Got it! Thanks

Rogue_Ant

NP