TOFD testing is performed according to the principle of irradiation of supersonic waves. For the inspection, two identical probes are arranged in a defined manner relative to each other, with one acting as the transmitter and the other as the receiver. In a defect-free weld seam, the surface wave and the backwall echo are detected. If there is a defect in the inspection area, it generates diffraction waves at its edges, which are detected by the receiver. The position and size of the defect can be calculated on the basis of the propagation time. For example, in the case of a vertical crack in a weld seam, the A-scan can show the lateral wave, the crack tip, the crack end and the backwall echo.
TOFD testing is performed according to the principle of irradiation of supersonic waves. For the inspection, two identical probes are arranged in a defined manner relative to each other, with one acting as the transmitter and the other as the receiver. In a defect-free weld seam, the surface wave and the backwall echo are detected. If there is a defect in the inspection area, it generates diffraction waves at its edges, which are detected by the receiver. The position and size of the defect can be calculated on the basis of the propagation time. For example, in the case of a vertical crack in a weld seam, the A-scan can show the lateral wave, the crack tip, the crack end and the backwall echo.
Last Change: 24.04.24
