Lambda value/ AFR correlation

[Frank F Parker]

> Hi Brad, I have a GM Service Technology Group document that lists AFR vs
> 02 voltage.
> 
> 
> A/F                        02 Volts
>    Ratio			   Range
> ========		   =============
> 
> 17.1			   0.090    0.110
> 16.5			   0.190    0.205
> 16.0			   0.290    0.310
> 15.5			   0.390    0.410
> 14.9			   0.490    0.510
> 14.4			   0.585    0.605
> 13.9			   0.680    0.700
> 13.2			   0.780    0.800
> 12.7			   0.870    0.890
> 12.1			   0.965    0.985
> 
> However I must say that this must be used with a caution. My experience
> 
This chart is NOT correct. Like a previous comment, it is way too linear.
The real curve is a square shaped S curve with most of the voltage 
change (eg:0.2-0.7) occuring in the region of about 0.5 on either side
of Lambda of 1.0 (14.7 a/f)

The NGK is quite good but expensive from Horriba. 

Bailey Engineering now sells a Special Bosch sensor and readout box to
accurately measure a/f in rich region. The NGK/Horriba or the Bailey
box is the ONLY accurate way to read a/f.

For the member who wanted the a/f vs Lambda, it is air/fuel div by
14.7=Lambda. Eg:

		A/F	Lambda
		17.64	1.20
		16.17	1.10
		14.70	1.00
		13.23	0.90
		11.76	0.80
etc

Frank Parker