Hysteresis effects in the slope calibration method for magnetometers

The slope method for calibrating vibrating sample magnetometers requires spherical samples of high permeability such that µ + 2/µ - 1 ≈ 1 It is shown that the presence of a small remanence in the calibration spheres results in an effective permeability that is as great if not greater than the initial permeability often used in the above equation. This even higher permeability further increases the validity of this approximation.