Coordinates of Injection region scan.
  
X = 0 for the measurements coordinates is -3 mm from the insert flat surface for the V notch.  

Coordinates of Field free region scan. 
 
The scan is from X = 42.5 mm to 12.5 mm in 2.5 mm steps 
and then from X = 12.5 to 3 mm in 0.5 mm steps, with the 
zero of this coordiante system being the injection side insert flat surface for the V notch.  
For the setup the wire was set to X= +17.5 in the above coordinate system and the stages zeroed.  
Thus X = 0 for the measurements is X = +17.5 mm for the septum coordinate system.