Structure and character analysis of a new type of steel wire rope NDT detector apparatus

A new type of steel wire rope non-destructive testing (NDT) detector apparatus is presented. It is composed of the magnetizer and the sensor array. The magnetizer, consisting of permanent magnets and armature, is used for magnetizing the steel wire rope to saturation. The high sensitive and giant magneto-resistance (GMR) micro sensor is adopted to inspect the inner and outer flaws of the steel wire rope. Some giant magnetoresistance sensors constitute the sensor array, distributed homogeneously and symmetrically. The differential signals are picked up and outputted for the following signal interpretation. In contrast with previous detectors, the detector can attain the precise and high sensitive measurement of the flaws. In the experiments, the steel wire rope with its diameter being 11 mm is adopted, and its surface flaws are detected. The experiment results show that qualitative detection of surface defects is attained. The apparatus can also be used for the flaw test of the ferromagnetic bars.