General view of the back of a chart recorder for a Bendix Corporation Time-of-Flight Mass Spectrometer. The Time-of-Flight Mass Spectrometer (TOFMS) was the flagship analytical instrument of the Bendix Corporation.

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 chart recorder is used to draw a graph (commonly known as a mass spectrograph or mass spectrum) that shows a peak for each ion detected. The position of the peaks is used to determine the mass-to-charge ratio, which is then used to identify the substances present in the sample.