Thus, as well as being credited with the invention of the first mass spectrograph, Thomson must also be credited with the invention of the mass spectrometer. One can readily see from these few paragraphs that the making of the history of mass spectroscopy has involved many scientists. In 1918, A.J. Dempster reported the construction of an electron bombardment ion source mass spectrometer of simpler design that Aston's mass spectrograph. Dempster's mass spectrometer could not be used for precise mass measurements, but it was better suited than Aston's mass spectrograph for measuring the relative abundances of the ionic species and was suitable for studying electron impact processes in gases. However, the full potentialities of the methods of mass spectroscopy were not realized with the early instruments, and not until 1942 was the first commercial instrument built by Consolidated Engineering Corporation and delivered to the Atlantic Refining Corporation.
Today there are a number of industrial organizations producing a wide variety of instruments.
By means of examples, Thomson even showed the possible use of mass spectrometry in the identification of the components of air. Yet, the first purely chemical application of mass spectroscopy appears to have been made by Conrad. Conrad published many very beautiful plates of groups of parbolas he obtained in studies of organic compounds and drew interesting conclusions from the appearances of the parabolas. One other use of the mass spectrometer or the mass spectrograph, which is of more than just historical interest, is that of isotope separation. Aston has reported that he had foreseen the use of the mass spectrograph for the separation of isotopes in 1922.