GB776370A - Arrangements for recording the results of the supersonic examination of metal parts - Google Patents

Abstract

776,370. Ultrasonic inspection devices. INSTITUT DE RECHERCHES DE LA SIDERURGIE. Oct. 15, 1954 [Oct. 28, 1953], No. 29725/54. Class 118 (2). [Also in Groups XXXIX and XL (b)] In ultrasonic examination of metals in which a trace appears on a cathode-ray oscillograph photo-cells associated with the screen operate means to produce a record of defects in the specimen. General arrangement (Fig. 1).-Pulses are produced and received by a piezo-electric transducer 9 which is traversed along the specimen in a number of parallel lines. The output of the detector is amplified, but instead of being applied to the Y plates, the X plates being provided with a linear sweep voltage, is applied to the grid of the cathode-ray tube 4 so as to make the trace visible only when the reflected pulse is received. Adjacent the screen of the cathode-ray tube is a row 5 of photo-electric cells (to be described). Thus the cell which is energized represents the depth of the defect. Each cell is associated with one of a number of styli 7 arranged transversely to a recording strip 8 synchronized with the transducer movement which thus make marks such as 14, 15 or 16 which represent by their position along the strip the position of the flaw along the specimen and by their position in a direction transverse to the strip travel the depth of the flaw. The pulse which marks the strip may also, or alternatively, be used to operate a warning loudspeaker. Transducer (Fig. 3).-A piezo-electric quartz transducer 9 is secured to rod 34 rigid with a stationary spindle 35. The quartz is contained in a liquid-filled chamber sealed by side-plates 36. A rubber case 37 held between side-plates 36 and further plates 38 closes the edge of the chamber and is such as to be flattened by the weight of the assembly so as to provide a good contact with the substance under test. Spindle 35 is supported in a yoke on rollers 39 and may be lifted by handles 40 (Fig. 1). The photo-cell assembly consists of a number of photo-cells 5 mounted on a curved block of transparent plastic material which fits the screen of the cathode-ray tube.