Calculating the factor and offset is easy.
To calculate the factor, we first must remove the offset. We do this by subtracting the value at 0v from the value at 5v.
19-9=10
This number is the value at 5v without the offset applied. To get the value per voltage we just divide this by 5 (volts).
10/5=2
Our factor is 2 and the offset (value at 0v) is 9.
Now we just apply the factor for the particular RAM variable that we are working with in ME7.
uushk_w voltage factor is 0.004883, so we multiply this by the voltage to AFR factor that we calculated for our new input.
0.004883*2=0.009766
ME7Logger applies a negative offset, so in order to use a positive offset we just need to flip the sign.
The values that we have been working with are AFR, therefore to convert our input to AFR:
Factor : 0.009766
Offset : -9
You can use the same method for Lambda, but keep in mind, if you are working backwards from AFR to Lambda, that the different manufacturers may use different factors from lambda to calculate AFR.