Ultrasonic Testing (UT)

Correctly interpreted

Ultrasonic testing must be carried out in accordance with defined guidelines. A high degree of experience is required for this test method in particular in order to correctly interpret the determined indications. While the probe is guided over the surface to be inspected, ultrasonic signals are emitted and reflections are received. This method is also used to determine wall thicknesses. Similar to echo sounder water depth measurement in shipping, ultrasonic testing enables the location of reflectors in a workpiece. Today, the pulse-echo method is mainly used. Ultrasonic pulses are introduced into the workpiece, which are received by the probe after a reflection (e.g. an error), after a certain time. The resulting echo provides information about the position and size of the display. Experience has shown that certain statements about the defect can be made from the appearance of a display.

• Localisation of the defect determined by the sound path and the angle of incidence
• Height of error echo compared to reference reflector allows conclusions to be drawn about error size
• Error orientation
• Echodynamics allows statement about error height
• Echoform, in conjunction with the error position, provides information on the extent, magnitude and type of the error

Applications

Ultrasonic testing is used for examinations of materials that conduct sound. Volume defects inside and outside of materials are detected:

• welding seams
• cast parts
• rolled material
• pipelines
• metal sheets
• coating thickness measurement