Apparatus for generating and measuring bending vibration in a non-ferromagnetic pipe without physical contact

摘要

An apparatus for generating and measuring bending vibration in a pipe buried underground or a pipe covered by insulating materials is disclosed. There is provided an apparatus for generating and measuring bending vibration in a non-ferromagnetic pipe without physical contact, comprising: a ferromagnetic strip adhered on a surface of the pipe; a coil wound around the surface of the pipe; two magnets for generating bias magnetic field, applied to the strip and parallel to the strip; a power source for supplying an electric current to the coil; and a measuring unit for measuring variation of voltage across the coil, the variation of the voltage being generated due to a strain according to inverse magnetostrictive effect, the strain being generated due to bending vibration, the bending vibration being generated due to deformation of the strip, the deformation being induced according to magnetostrictive effect as the power source supplies the electric current to the coil.