Sputtering from ion-beam-roughened Cu surfaces

This invention relates to an instrument for measuring the degree of an internal taper and comprises a cone having an inclined surface which increases in diameter from its inner to its outer end and is moved axially within a tubular sleeve by an actuating screw. Three identical longitudinal measuring members are pivotally attached to said tubular sleeve at their forward ends and supported resiliently at their rearward ends. Adjustable abutment members projecting inwardly of said measuring members contact the surface of said cone.