Cap inspection and manufacture

An inspection apparatus for testing of objects having a cavity defined by a sidewall and bottom wall, the apparatus comprising:

• a supply conveyor providing at least one single-file line of objects in contact with each other;
• an object receiver arranged to receive said single-file line of objects from said supply conveyor and provide spacing of said objects;
• a transportation unit associated with said receiver for conveying said objects spaced by said receiver;
• a spark test wheel having probe fingers rotatably mounted over said transportation unit;
• at least one opposed spark test electrode associated with said transportation unit;
• and
• a synchronized drive for driving said object receiver, said transportation unit and said spark test wheel so that said probe fingers of said spark test wheel can rotate into the cavity of said objects without contacting the sidewall of said objects while contacting and pressing said bottom wall from inside said cavity against said opposed spark test electrode contacting said bottom wall from an outside of said cavity to perform a spark test of said objects.