Field-cycling NMR relaxometry is a well-established technique that can give information on molecular structure and dynamics of biological systems. It provides the nuclear relaxation rates as a function of the applied magnetic field, starting from fields as low as ~ 10⁻⁴ T up to about 1–3 T. The profiles so collected, called nuclear magnetic relaxation dispersion (NMRD) profiles, can be extended to include the relaxation rates at the largest fields achievable with high resolution NMR spectrometers. By exploiting this wide range of frequencies, the NMRD profiles can provide information on motions occurring on time scales from 10⁻⁶ to 10⁻⁹ s. ¹H NMRD measurements have proved very useful also for the characterization of paramagnetic proteins, because they can help characterise a number of parameters including the number, distance and residence time of water molecules coordinated to the paramagnetic center, the reorientation correlation times and the electron spin relaxation time, and the electronic structure at the metal site.

场循环核磁共振弛豫技术是一种成熟的技术，可以提供有关分子结构和生物系统动力学的信息。它提供了作为外加磁场函数的核弛豫率，从低至约 10 ^-4 T 的场到约 1-3 T。如此收集的分布，称为核磁弛豫色散 (NMRD) 分布，可以扩展到包括高分辨率 NMR 光谱仪可实现的最大场的弛豫率。通过利用这种宽范围的频率，NMRD 剖面可以提供关于在 10 ^-6到 10 ^-9 s 的时间尺度上发生的运动的信息。¹H NMRD 测量已证明对顺磁蛋白质的表征也非常有用，因为它们可以帮助表征许多参数，包括与顺磁中心协调的水分子的数量、距离和停留时间、重新定向相关时间和电子自旋弛豫时间，以及金属位点的电子结构。