Comparison of calibration systems for magnetic field measurement equipment

The current ANSI/IEEE standard specifies two possible methods for magnetic meter calibration: a single square loop or a round Helmholtz coil. However it: (a) does not specify the size of the coil; and (b) does not provide a comparison of the field uniformities between the two suggested systems. In this paper, the z-directed magnetic field equations for four calibration system designs, the single round loop, the round Helmholtz coil, the single square loop, and the square Helmholtz coil are derived and presented.>