The latest LC-1 manual describes the outputs as follows:
Therefore, based on the above statement, I end up with the following new formula...As factory programmed the first output simulates a typical narrow band oxygen sensor. The second output is programmed to output between 0 V for an AFR of 7.35 (gasoline) and 5.0V for an AFR of 22.39. Other curves of course are easily programmable
AFR = (({EXT.AD1})*3.008 )+7.35
***Note: 3.008 is derived by obtaining the gradient: (22.39 - 7.35)/(5 - 0) = 3.008 ***