Magnetic field generator for the calibration of magnetometers and electromagnetic compatibility (EMC) and electromagnetic interference (EMI) compliance

A standard magnetic field generation system from 1 to 30 mu T between DC and 20 kHz has been demonstrated for the calibration of DC/AC magnetometers. The system includes a laboratory-designed Helmholtz coil, shunt resistor, digital multimeter, and dedicated power source. The DC coil constant of the Helmholtz coil was determined to be 10.586 mu T/A using a single-axis fluxgate magnetometer. The homogeneity analysis was carried out for the Helmholtz coil to identify the uniformity along the x, y, and z axes. The system for DC generation was standardized and compared by measuring the field values using a single-axis fluxgate magnetometer. Further, the system was validated for AC generation by a search coil with a known turn area (1.3767 +/- 0.0027 m2). Moreover, the measured magnetic field values using a search coil were compared with a commercial magnetometer to identify the variation in generated and measured magnetic fields. The described system can have significant utilities in calibration, electromagnetic interference electromagnetic interference/electromagnetic compatibility (EMI/EMC) testing, magnetic susceptibility testing, and magnetic field therapy applications. The expanded uncertainty of the Helmholtz coil in generating a magnetic field was 0.2-1.6% (at k = 2) from DC to 20 kHz.