Fourier Transform (FT)

The Fourier Transform, or FT, is a mathematical operation that analyzes complex signals and identifies its frequency components. An NMR signal, called a free-induction decay (FID), is composed of one or more oscillating components that decay with time. The FT sorts out the various frequencies present, and displays them as a spectrum, in which each component is shown as a peak. Its position depends on the value of the frequency (in Hz); its intensity, on the relative intensity of that component; and its width, on the decay constant.