9 Scientific apparatus and instruments, namely, photon-detecting instruments, low-noise amplifiers, noise discriminators, light-detecting instruments, electron tubes, radiation detectors, radiation-measuring instruments, voltage regulators, voltage stabilizers, calibration sensors; electron multipliers; photomultipliers; thermionic devices, namely, thermionic tubes, thermionic valves; sensors for detecting light or other electromagnetic radiation scintillators; electronic controllers equipment for all or any of the foregoing; voltage dividers; housings for electronic apparatus, instruments and equipment; housings for electrical apparatus, instruments and equipment; computer housings; housings for electrical measuring apparatus; amplifiers; amplifier-discriminators; counters and counting instruments for use in photon counting; electronic counters use in photon counting; electrical and electronic counter-timers and photon-counting modules; connection cables; computer cables; coaxial cables; electric data transmission cables; electric cables; electronic cables; fibre-optic cables; electrical sockets; electric power supply units; laboratory power supply apparatus, namely, electrical power suppliers for use in laboratories; portable power supply apparatus, namely, portable electrical power suppliers; electronic circuits; switching circuits, namely, electric switching circuits; magnetic shields, namely, shields for use in protecting photomultiplier tubes and scintillation counting tubes from external magnetic fields; oscilloscopes; electrical conductors; electrical conduits; electrical connectors; electric connector boxes; electric sockets; coaxial electrical connectors; electrical connectors for use with electronic circuits, fibre-optics and circuit boards; electric cable connectors, coaxial cable connectors; temperature controlling apparatus for use with all or any of the foregoing; computer software for use in operating and controlling photomultipliers, light-detection, photon-detection, photon-counting and calibration machines and systems; downloadable computer programs for use in operating and controlling photomultipliers, light-detection, photon-detection, photon-counting and calibration machines and systems; downloadable electronic publications, namely, brochures, leaflets, pamphlets, flyers, data sheets, books, booklets, guides, manuals, posters, magazines, journals, periodicals, newsletters, reports, information cards, photographs, instructional and teaching materials in the fields of light-detection, photomultipliers, photon-detection, photon-counting and calibration