GB1004870A - Ultrasonic testing - Google Patents

Abstract

1,004,870. Ultrasonic testing. J. KRAUTKRAMER, and H. KRAUTKRAMER. Nov. 8, 1961 [Nov. 9, 1960], No. 40014/61. Heading H4D. Longitudinal faults 10 (Fig. 3), transverse faults 11 and faults such as pores in a weld seam 12 are separately distinguished by an arrangement employing two ultrasonic transmitting transducers 1, 2 and two receiving transducers 3, 4 the operation being that a longitudinal fault 10 causes transducers 3 and 4 to respond to reflected energy emitted by heads 1 and 2, respectively, whilst a transverse fault 11 causes the heads 4 and 3 respectively to respond to heads 1 and 2. When the fault is a pore the relatively omnidirectional nature of the reflection produces an indication of both longitudinal and transverse faults. The four transducers are mounted at the corners of a rectangle such that the seam 12 bisects two opposite sides and as the assembly is moved along the seam the echo signals as viewed on a luminescent monitor screen (which may also be a recording monitor) trace a path as shown in Fig. 4a in the case of longitudinal faults or, as shown in Fig. 4b, in the case of transverse faults. The invention is applicable to testing seams in plates and longitudinal and helical seams in tubes. In the latter case in order to test the seam at the end of the tube each transducer is switched for operation as a common transmitter/receiver and the transducers are rotated to beam energy perpendicular to the seam, the seam being then tested in a known manner as described with reference to Figs. 1 and 2 (not shown).