对比球体和圆柱体的测量结果表明：一个轴比（axia1 ratio）（长度/直径）≈0.9，磁化率≈0.8（CGS）的短圆柱体，它在轴向和径向的有效退磁系数N≈3.7。因此，磁化率大的短圆柱体在三个互相垂直方向的有效退磁系数的和小于4π。在测定强磁性磁铁矿标本的磁性时，这点颇为重要。 The measurement results of the comparison sphere and the cylinder show that a short cylinder with an axia1 ratio (length / diameter) of ≈0.9 and a magnetic susceptibility of ≈0.8 (CGS) has an effective demagnetization factor in the axial and radial directions of N≈ 3.7. Therefore, the sum of the effective demagnetizing factors of short cylinders with high magnetic susceptibility in three mutually perpendicular directions is less than 4π. This is important when determining the magnetism of a ferromagnetic magnetite specimen.