AFR-Volts Chart

[TomoHawk]

I would like to build an AFR meter using an Arduino board, and I would like to know if anyone has a detailed chart of voltage v AFR for a narrow-band oxygen sensor. 

Yes, I searched for a  long while, but you guys usually have useful engine data.  There are lots of chart images, but they all look like a curvey Z, so obviously, there isn't enough detail to pick out coordinates to plot in a spreadsheet.

If I had a chart or table with enough detail, I could generate a formula  or a lookup table.  The former would be better.

It's just too bad the LCD displays are monochrome, because colour would be easier to interpret while driving,  I suppose I could add some colored or RGB LEDs.

thxZ

 

[240260280]

You also need to track the 12V voltage as the AFM/ECU does this and compensates for running at 11.5V to 15Vish range.

[jonbill]

http://www.edproject.co.uk/NarrowAFR.html

[TomoHawk]

Thanks, but that guy's data doesn't make sense, and he says it's not correct, especially for lambda=1. He gives 0.33V  for lambda=1.0 but it should be about .45V . Then says he used a wide-band controller to get measurements from a narrow-band sensor?   He also needs to change the way he explains the theory of the sensor, as he says the fuel "pulls oxygen through"  for both rich and lean conditions.

That's why I passed this page the first time I viewed it.

Edited February 9, 2019 by TomoHawk

[Zed Head]

15 hours ago, TomoHawk said:

Yes, I searched for a  long while, but you guys usually have useful engine data.  There are lots of chart images, but they all look like a curvey Z, so obviously, there isn't enough detail to pick out coordinates to plot in a spreadsheet.

You'll have to measure temperature also, as shown in your plot, even with a lookup table.

Why use a narrow band when wide bands are available?

[TomoHawk]

What are Wide Bands?  Painted bands?  Rubber bands?

Edited February 9, 2019 by TomoHawk

[Zed Head]

https://www.haltech.com/wideband-o2-sensors-explained/

[TomoHawk]

I'm not interested in buying electronic instrumentation from Haltech.

Edited February 10, 2019 by TomoHawk

[Zed Head]

Narrow band is very limited in application.  Wide band gives you what you said you wanted.  Unless you're really trying to "outdo" the engineers that didn't make narrow band sensors work for AFR measurement.  Or you aren't looking for accuracy.  Good luck.

https://en.wikipedia.org/wiki/Oxygen_sensor#Wideband_zirconia_sensor

http://www.walkerproducts.com/o2-sensor-training-guide/history/

[TomoHawk]

The so-called wide-band sensors aren't compatible with Arduino electronics.

If you buy one and send it to me, I might consider using it. 

Edited February 10, 2019 by TomoHawk

[Zed Head]

17 hours ago, TomoHawk said:

I would like to build an AFR meter using an Arduino board, and I would like to know if anyone has a detailed chart of voltage v AFR for a narrow-band oxygen sensor. 

You said you wanted narrow band...?

Just trying to help.  Good luck.

[TomoHawk]

Yes, I'll be using a Narrow-band Oxygen sensor.