{HEAD ~ The present invention} provides a friction testing machine and method for measuring friction characteristics between a test sample and {TAIL ~ a friction surface} 
{ HEAD ~ The present invention } provides a friction testing machine and method for measuring friction characteristics between a test sample and { TAIL ~ a friction surface }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL