Many different technologies have been developed to measure magnetic field strength. Borrowing a representation originally developed by the CERN, the diagram below classifies them according to rangeThe range of a probe is defined by the minimum and maximum field strength it can measure. On an instrument,... and precisionPrecision is how closely multiple measurements will be clustered. Also called reproducibility or repeatability. In everyday speech, often confused with.... 

Metrolab masters four technologies: Nuclear Magnetic Resonance (NMRNuclear Magnetic Resonance. A resonance phenomenon seen when you irradiate a sample in a magnetic field with an RF field....) and Electron Paramagnetic Resonance (EPRElectron Paramagnetic Resonance – same as ESR....), Fluxmeters, Hall and Fluxgate. These cover a flux-density rangeThe range of a probe is defined by the minimum and maximum field strength it can measure. On an instrument,... of ten orders of magnitudeThe magnetic field is a vector quantity. We may be interested in its individual components or its total magnitude...., and include the world’s most precise techniques.