collimator optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens; light rays leave the slit as a parallel beam
mass spectrometer,
spectrometer spectroscope for obtaining a mass spectrum by deflecting ions into a thin slit and measuring the ion current with an electrometer
optical prism,
prism optical device having a triangular shape and made of glass or quartz; used to deviate a beam or invert an image
