High accuracy magnetic field measurements with a Hall probe

A silicon-based temperature stabilized axial Hall probe with an absolute accuracy of +/-40 ppm in the full range between 0 and 6 T is presented. The absolute calibration of the probe is performed against a nuclear magnetic resonance (NMR) probe. The application of the probe to a magnetic field profile of a 5 T superconducting magnet system, with field gradients as high as 30 T/m, reaching an overall accuracy of better than +/-100 ppm, is demonstrated. In addition to the high absolute accuracy, this Hall probe allows high spatial resolution measurements of inhomogeneous fields in configurations where present NMR probes are not usable. (C) 1999 American Institute of Physics. [S0034-6748(99)01506-3].