Improvements in and relating to the non-destructive testing of solid bodies using ultrasonic vibrations

Abstract

Abstract 718,291. Testing materials by ultrasonic vibrations. KELVIN & HUGHES, Ltd. March 13, 1953 [Dec. 13, 1951], No. 29272/51. Class 118 (2) In a pulse-echo ultrasonic flaw detector with a cathode-ray tube indicator, the cathode-ray beam is deflected in one direction in correspondence with movement of the transducer unit over the surface of the work piece and is deflected in a perpendicular direction by the echo pulses. As shown the transducer unit comprises mechanically-connected transmitting and receiving transducers 17, 19 coupled to the surface of the work piece by probes 10, 11, the unit being linked to the slider 12 of a potentiometer 13 which is connected to one deflecting plate 14 of the cathode-ray tube 15, the perpendicular deflecting plate 21 being connected to the receiver 20. The transmitting transducer 17 is connected to a pulse generator 16 and in order to prevent display of the transmitted pulses and of echoes from the bottom surface of the work piece, the cathode-ray beam is gated on during the required period by a control pulse from generator 18 coupled to generator 16; alternatively the control pulse may be applied to gate receiver 20. The range of a flaw is determined by causing the trailing edge of the control pulse to occur progressively earlier until the response produced by the flaw just disappears. The range may also be determined by a separate cathode-ray tube with a type-A display or the tube 15 may be switched to give such a display. Specification 696,926 is referred to.

Inventors

• 👤 William Halliday
• 👤 Herbert Martin Jefferys

Bibliographic Details