FIGS 5A and 5B illustrate a relatively uniform rate of {HEAD ~ motion} of the fiber optic pair to and from {TAIL ~ the surface} of the object being measured  
from
FIGS 5A and 5B illustrate a relatively uniform rate of { HEAD ~ motion } of the fiber optic pair to and from { TAIL ~ the surface } of the object being measured
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH