Probe coil for whirling crack detection

Abstract

Abstract PURPOSE:To perform accurate inspection in a short time by a method wherein plurality of coils are arranged in the form of concentric circles to make a local magnetic field so as to detect the varying impedance of coil caused by a whirl current generated at said part. CONSTITUTION:In the circular probe coils 3A and 3B having different diameters and circularly wound about in the same number of turns and arranged concentrically, one end 4C of each wire is connected each other while the other ends 4A and 4B are made into the feeding elements. When to said probe coils the junction part, which is the inspection part of the material to be inspected, is put to let flow the currents with the same frequency, same amplitude and the antiphase, a magnetic field is generated at a circular part surrounded by both probe coils and being given said magnetic field the whirl current flows through the material to be inspected. In case the abnormality exists in the junction part of the material to be inspected the varied impedance of the coil detects it.

Inventors

• 👤 Hitoshi Tanaka

Bibliographic Details