GB1089742A - Improvements in or relating to the non-destructive testing of materials - Google Patents

Abstract

1,089,742. Ultrasonic flaw-detection. PRVNI BRNENSKA STROJIRNA ZAVODY KLEMENTA GOTTWALDA, NARODNI PODNIK. March 30, 1965 [April 2, 1964], No. 13443/65. Heading H4D. In an ultrasonic pulse-echo flaw detector for inspecting a revolving body in a manner such that the formation and behaviour of flaws under centrifugal stress conditions may be studied, the pulses are transmitted at intervals such that each pulse is reflected from the same point within the body. In the embodiment of Fig. 1, the transmission of a pulse from a single transmitter-receiver transducer 4 is synchronized with the rotation of the body, 5, by means of an electrical pick-up device 1 and a phase-shift controller 2. Controller 2 permits the transmission of a pulse at any angular position of the body 5 relative to a fixed point 8 of the body 5. Echo pulses from a flaw 6 are fed to an indicator 3, and a stroboscope 9 may be coupled to the controller 2. Coupling fluid is fed to the transducer 4 through piping 7. To enable flaw echoes to be received at high rotational speeds of the body 5, when the distance between the transducer 4 and flaw 6 is large, or when the transducer 4 has a small diameter, two transducers 4 may be used (Fig. 2, not shown), the transducers being circumferentially spaced on a circle coaxial with the axis of rotation of the body 5. Provision may be made for moving the transducer(s) 4 circumferentially.