Without calling them, their website says 10:1 to 20:1. So assuming 10:1 is 0V and 20:1 is 5V, then the formula is AFR = (2)*(TGV Voltage)+(10). If you need an excel formula, and we assume that TGV 1 data is in Column A starting in Row 2, then it is "=2*a2+10". You really need to call them to find out what the corresponding values are though.
