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