摘要 |
PCT No. PCT/GB94/01022 Sec. 371 Date Nov. 16, 1995 Sec. 102(e) Date Nov. 16, 1995 PCT Filed May 12, 1994 PCT Pub. No. WO94/28407 PCT Pub. Date Dec. 8, 1994The absolute values of biaxial stresses in a ferromagnetic material (16) are measured using a probe (12) which comprises an electromagnet (26), a sensor (32) for stress-induced magnetic anisotropy (SMA) and a sensor (30) for directional effective permeability (DEP). The DEP sensor (30) enables absolute values of stress to be determined; the SMA sensor (32) enables the directions of the principal stress axes to be accurately determined, and improves the accuracy of the stress measurements. |