[ Particle accelerators; magnets; electromagnetic coils; ] testing apparatus not for medical purposes, namely, electron probes and ion probes; apparatus and instruments for astronomy, namely, analytical instruments in the nature of analyzers for measuring meteorites; [ regulating apparatus, namely, apparatus for regulating electric current; ] detectors, namely, [ charged particle detectors, ] atom detectors [ and photon detectors ] ; [ vacuum gauges; ] data-processing apparatus, namely, elect...