Abstract: A method of eddy-current flaw detexction where an exciting device and a receiving device are held in the vicinity of a conductor. An eddy current is generated in the conductor by a primary magnetic field generated by excitation, thereby generating a secondary magnetic field, wherein the state of the magnetic field is detected by the receiving device. The exciting device includes a coil and an iron core. The coil has a first current line and a second current line in which electric current flows in opposite directions. The iron core is gate-shaped in cross section and includes a first leg portion, a second leg portion, and a beam portion. The receiving device is disposed in a corner between the second leg portion and the conductor, on a side opposite the second current line on the outer side of the iron core.

Abstract: A capacitive proximity sensor giving a long front detection range with less erroneous detection. A capacitive proximity sensor detects an approach of an object such as a human body or so by its capacitance change. The capacitance in a capacity composed by a first electrode and a second electrode in the sensor varies according to the approach of the object in distance. The first electrode (1) is in a linear shape at a small surface area such as an electric wire. The second electrode (2) is in a planar shape at a large surface area such as a flat plate or a sheet. The first electrode (1) and the second electrode (2) are arranged in parallel at a separation. A front detection region in front of the capacitive proximity sensor is at a side where the first electrode (1) appears upon the second electrode (2). A shield electrode (8) is placed behind the second electrode (2) face to face in parallel at a separation. The shield electrode (8) is grounded.

Abstract: In detecting a flaw by generating an eddy current in a conductor, it is enabled to easily detect a flaw in the vicinity of a back surface of the conductor. An exciting device and a receiving device are held in the vicinity of a conductor, and an eddy current is generated in the conductor by a primary magnetic field generated by excitation, thereby generating a secondary magnetic field, the state of the magnetic field is detected by the receiving device. The exciting device includes a coil and an iron core. The coil has a first current line and a second current line in which an electric current flows in opposite directions. The iron core is gate-shaped in cross section and includes a first leg portion, a second leg portion, and a beam portion. The iron core is oriented such that an opening thereof on a side opposite to the beam portion faces the conductor. The first current line of the coil is disposed on an inner side of the two leg portions of the iron core.