{HEAD ~ Apparatus} 17 wherein the included angle of the tapering section is at least twice the angle whose tangent equals the static coefficient of {TAIL ~ friction} between the test contact member and the test probe 
{ HEAD ~ Apparatus } 17 wherein the included angle of the tapering section is at least twice the angle whose tangent equals the static coefficient of { TAIL ~ friction } between the test contact member and the test probe
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH