Defects in colour

Citation

(1999), "Defects in colour", Aircraft Engineering and Aerospace Technology, Vol. 71 No. 6. https://doi.org/10.1108/aeat.1999.12771fad.005

Defects in colour

Keywords Sonatest, Ultrasonic, Flaw detection

The ultrasonic flaw detector manufacturer, Sonatest plc, reports that it now offers a complete range of digital ultrasonic flaw detectors with coloured displays. Defect detection using manual ultrasonics is by no means a simple task. It becomes even more complex when testing components with natural reflectors, such as section changes in axles and rotor shafts, or root and cap signals in weld inspection. Any means of assisting flaw detection must be considered a huge benefit.

According to Sonatest, only its digital ultrasonic flaw detectors currently use a colour display. This it claims, has led to the creation of a unique fingerprint feature. A reference signal is now stored on the screen in one colour whilst simultaneously viewing the actual scan in a different colour. In effect coloured defects jump out of the reference signal and shout "Hey, here I am".

This technique may theoretically be applied to a wide variety of applications such as bond integrity, spot welds or even in-service crack growth monitoring. For weld testing the echo dynamic pattern (envelope) of a scanned good section of weld using peak memory mode is stored as the reference signal.

For critical root scans the maximised signal obtained from the bead may be stored as the reference signal. Lack of root fusion or penetration is then stated to be more easily identified by the colour mismatch as a result of timebase (and amplitude) variations. These variations are normally about 2mm less than the natural bead reflector.

This novel feature is believed to be a beneficial aid to manual ultrasonic flaw detection. The reference waveform feature aids technicians with rapid and confident defect detection.

Details available from Sonatest plc. Tel: +44 (0) 1908 316345.