{HEAD ~ a coupling device} which removably couples {TAIL ~ the portable measurement device} to a port in the moveable barrier operator, the measuring circuit generating an impact force signal representing an impact force measurement and effecting transmission of the impact force signal from the interface to the movable barrier operator 
removably couples
{ HEAD ~ a coupling device } which removably couples { TAIL ~ the portable measurement device } to a port in the moveable barrier operator , the measuring circuit generating an impact force signal representing an impact force measurement and effecting transmission of the impact force signal from the interface to the movable barrier operator
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH