Abstract: A system for NMR assessing a sample or a series of samples in turn which comprises means for applying a static magnetic field in a first direction through the sample, pre-polarizing means for first applying a magnetic field in substantially the same direction to the sample, means for applying an alternating excitation magnetic field in a second different direction through the sample, means for sensing energy emitted by the sample in response to the excitation magnetic field, and means arranged to provide an indication of an assessment of the sample based on the energy emitted by the sample in response to the excitation magnetic field.