When my 180 arrived years back, I was at a loss to work out if the markings were directly related to position > amps/wirespeed as per the dials i.e. was each division equal, or on a 'sliding' scale. Unable to work it out , I phoned R-Tech and asked. Very helpful lady transferred me to one of their tech team....who didn't have the answer.
I wonder if my question prompted some testing at their end spawned the above document . I'm going to print that out, laminate it and have it in the cave soon.