a force measurement device for obtaining {HEAD ~ a measurement} indicative of {TAIL ~ the frictional force} resisting movement of the sample as it is moved in said first direction 
indicative of
a force measurement device for obtaining { HEAD ~ a measurement } indicative of { TAIL ~ the frictional force } resisting movement of the sample as it is moved in said first direction
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH