9 ELECTRICAL APPARATUS AND INSTRUMENTS, CHECKING, AND WEIGHING APPARATUS AND INSTRUMENTS-NAMELY, ELECTROSTATIC POWDER SPRAY; METAL DETECTORS; PINHOLE DETECTORS FOR PLASTIC FILMS, LININGS, CLADDINGS AND ANY OTHER NON ELECTRIC-CONDUCTIVE SEALING MATERIALS; SEALING DETECTORS FOR BOTTLES AND CANS AND METAL WEIGHT CHECKERS