Diffusion coefficients provide a measure for how fast components move in a given mixture. This may be caused by Brownian Motion or concentration differences (gradients). Respectively, self diffusion and mututal diffusion coefficients are determined to describe the movement.

The knowledge of exact values for these coefficients is of great help in many fields of engineering, such as process engineering or plant construction.

NMR provides a versatile tool of measuring diffusion coefficients. By applying magnetic gradient fields, space resolution is achieved and movement in a sample (and therefore diffusion) can be monitored.