THE BALL BAR (DUMBBELL) RANGER PERFORMS EXACTLY THE SAME FUNCTION AS A STANDARD BALL BAR (DUMBBELL) FOR LASER TRACKERS AND PORTABLE COORDINATE MEASURING MACHINES. IT WILL ALSO ACT AS A TRACEABLE CALIBRATION DEVICE FOR TELESCOPING BALL BAR (DUMBBELL)S. THE RANGER CONSISTS OF TWO EXTREMELY ACCURATE THREE BALL KINEMATIC COUPLING MADE OF INVAR® THAT ARE SUPPORTED A FIXED DISTANCE APART BY A RIGID INVAR® TUBE (SEE FIGURE #1A.). WHEN THIS ABSOLUTELY FIXED DISTANCE BETWEEN THE KINEMATIC COUPLINGS IS MEASURED IN THE 20 TO 35 POSITIONS SPECIFIED BY THE ANSI B89.4.1-1997 STANDARD, A FULL EVALUATION OF THE LASER TRACKER OR PORTABLE C.M.M. IS MADE.