Abstract: There is provided a mass spectrometer having a gas inlet system for introducing a sample into the ion source of the spectrometer which inlet system includes a cold trap for condensing a sample. The inlet system is provided with means for detecting the pressure therein and means for automatically controlling the operation of the cold trap in dependence on the detected pressure whereby the sample is automatically condensed in the cold trap when it is present in a small quantity. Around the cold trap is conveniently a coolant passage through which coolant from a coolant reservoir is drawn.

Abstract: Charged-particle spectroscopy apparatus for the chemical analysis of a sample in which an apertured plate receives charged particles emitted from the sample and transmits them to an analyzer for analyzing the energies of the particles, the aperture of the plate being such as to restrict the particles passing therethrough to a pencil beam of particles from a selected area of the sample.