Nuclear Magnetic Resonance

Nuclear magnetic resonance is an indirect method for determining moisture content.

In this method, a sample is placed in a static magnetic field and radio frequency energy is applied at a specific frequency related to the strength of the applied magnetic field. The radio frequency is applied for a specified time which is determined by the design of the instrument. Immediately afterward, a signal is generated in the receiving coil. Moisture content is related to the initial amplitude and / or the decay characteristics of the signal. The results from this method can be calibrated against standard techniques allowing moisture content to be predicted from the output voltage. A detailed explanation is beyond the scope of this module. A great number of books have been written which describe this procedure. They are available in most research libraries.