Adjusting the operating parameter could be based on {HEAD ~ a difference} between a measured anisotropy of the first surface and {TAIL ~ a measured anisotropy} of the second surface 
between
Adjusting the operating parameter could be based on { HEAD ~ a difference } between a measured anisotropy of the first surface and { TAIL ~ a measured anisotropy } of the second surface
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH