Here is my suggestion.
Take a look at: http://rubatoguy.home.mindspring.com/newafm.html
You will notice 11 discrete places along the track where the circuit board
touches the carbon track.
I'd recommend that everyone who tests their AFM use these points as a standard
reference point so that everyone measures at the same place. Also Note how many
notches the wheel is from the 500 marking.

Todd

'88 westy

Jay L Snyder wrote:

> I  could measure the resistance across the range of the tracks at several
> points by just moving the arm and this would effectively ignore the spring
> tension settings.  If I understand correctly, the spring tension regulates
> the amount of arm movement for the given amount of air flow through the AFC
> measured by the "flapper" (for lack of a more technical term).   Arm
> movement is different than the internal flapper movement?
>
>                                                              Jay