NMR = Nuclear Magnetic Resonance is the resonance that occurs when a nucleus
(usually hydrogen, but any nucleus that has non-zero spin will work) is placed in a
magnetic field and is 'swept' by a radio frequency that causes the nuclei to
This causes the radio frequency to be absorbed, which is what is measured.
MRI = Magnetic Resonance Imaging is a more complex application of NMR in which the
geometric source of the resonances are detected and deconvoluted by Fourier
ESR = Electron Spin Resonance is also a resonance phenomenon, except in this case
it is the spin of an unpaired electron that is in resonance, rather than a nuclear
Answered by: Vince Calder, Ph.D., Physical Chemist, retired
'There must be no barriers for freedom of inquiry. There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors.'