9 ELECTRICAL AND ELECTRONIC EQUIPMENT, AND MEASURING, INDICATING AND CHECKING DEVICES AS WELL AS INSTRUMENTS FOR SCIENTIFIC PURPOSES CONSISTING OF CALCULATING MACHINES, ELECTROCHEMICAL STORAGE CELLS-NAMELY, FUEL CELLS, ELECTRIC CELLS AND BATTERIES, BATTERY CHARGERS, TELEMETERING APPARATUS, AMMETERS, SWITCHES, VOLTMETERS, BAROMETERS, THERMOMETERS; OPTICAL DEVICES AND INSTRUMENTS-NAMELY, MICROSCOPES, LENSES, SPECTACLES AND SLIDE VIEWERS; PHOTOGRAPHIC APPARATUS AND PARTS THEREOF-NAMELY, EXPOSURE ELEMENTS, DROP SHUTTERS AND VIEWFINDERS, PROJECTORS AND PARTS THEREOF; PHONOGRAPHS RECEIVERS AND PARTS THEREOF, WIRELESS TRANSMISSION INSTRUMENTS-NAMELY, AMPLIFIER TUBES; ELECTRIC LIGHTERS; AND ELECTRIC PORTABLE VACUUM CLEANERS FOR DOMESTIC USE