O2 voltage vs A/F

[JTR]

Vehicle - 2001 DC5 Type R(JDM)
ECU number 37820-PRC-013

I live in JAPAN and use K-Pro(PRC-013) for my DC5 TypeR .
I guess A/F displayed on KManager is calculated by 02sensor voltage .
So I try to get O2sensor voltage by OBD K-Line and understand that it is 02sensor voltage
displayed on KManager .
I want to know relatinship between 02sensor voltage displayed on KManager and A/F ,
Graph or numerical formula is OK .
Please teach me .

[Spunkster]

The OEM wideband is not voltage based, it is current based and requires a controller inside the ECU to be read and displayed.