This might help. It's what I used. I'm sorry I but I didn't use a multimeter. I just made a tiny adjustment and my motors ran fine and ran cooler. You could probably go by temperature but probably not very scientific. During a print measure with a laser thermometer. Then turn the pot a tiny bit, say 1/16 to 1/8 turn. Measure the temp again. If it's around 160 then your are done. That's a good temp. Mine were running around 180 to 190F. Now they run between 1505 and 160F and are plenty strong and precise.

http://bootsindustries.com/portfolio...s-adjustments/