摘要 |
An NMR (=nuclear magnetic resonance) probe head comprising an RF (=radio frequency) receiver coil system, which can be cooled down to cryogenic temperatures, and a room temperature pipe (5), extending in a z direction, for receiving a sample tube (6) containing sample substance to be examined by NMR measurements is characterized by a centering device (10) for centering the sample tube (6) in its measuring position about the axis of the room temperature pipe (5) to thereby provide simple and substantial reduction in the temperature gradient in the z direction during operation without thereby impairing the NMR measurement.
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