Magnetic resonance methods for NDE

The magnetic resonance methods considered useful for NDE applications are part of the broad category of radiofrequency resonance absorption spectroscopy techniques tabulated in the present paper. Of the techniques listed, nuclear magnetic resonance (NMR), nuclear acoustic resonance (NAR), and electron magnetic resonance (EMR) are magnetic resonance methods. While in the discussion the more versatile NMR method predominates, the NAR method is suitable for certain measurements in metals and the EMR is useful for evaluation of materials containing unpaired electrons which result from broken bonds, incomplete pyrolyzation, free radicals, strains, etc. In conclusion, magnetic resonance can be used to perform useful qualitative and quantitative analyses on many types of materials quickly and nondestructively.