The effect of the angle of inclination of the exciting coil in electromagnetic-thermal non-destructive inspection

The effect of inclination of the exciting coil in electromagnetic-thermal non-destructive inspection of conductive plates is investigated numerically. Coils of finite height and planar coils, with circular or square section, are considered in various configurations. The heating of the plate is most effective when the coil inclination is 0° or 90° and less effective for intermediate angles of inclination. The heating by the planar coils is most effective for inclination of 0° and by the coils of finite height for inclination of 90°. The coil tilt reduces the detection region. However, a coil with 90° inclination gives better results in the detection of cracks situated at the centre of the detection region.