Diagram depicting the continuous ionization operation of a Bendix Corporation Time-of-Flight Mass Spectrometer. Ionization is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons to form ions, often in conjunction with other chemical changes.

Mass spectrometry is an analytical technique used to identify qualitatively and quantitatively the atomic and molecular composition of inorganic and organic materials by sorting ions according to their mass-to-charge ratios. The Time-of-Flight Mass Spectrometer (TOFMS) was the flagship analytical instrument of the Bendix Corporation.