Detection of discontinuities

Principle
The experiment demonstrates the application and performance of various non-destructive test methods with the aid of ultrasound. A test object with different types of discontinuities is used to perform various detection methods. First, the test object is scanned in order to determine which detection method is suitable for which type of defect. Then, the signal-to-noise-ratio is determined for each discontinuity with a straight beam probe, angle beam probe, and a transmitter-receiver probe (TR probe). This is followed by a discussion of the results in view of the selection of the most suitable detection method for a specific task.

Benefits

• Complete echoscopy system incl. test objects to perform different NDT techniques
• With the same equipment angle beam inspection and TOFD can also be performed
• Display of measurement values as with a diagnostic system

Tasks

1. Use a 2 MHz straight beam probe (vertical scanning direction) to define the suitable device parameters at the ultrasonic echoscope. Produce a B-scan of the test object.
2. Assign the various defects (discontinuities) of the test object to the B-scan. Then, determine the signal-to-noise-ratio for each discontinuity in the A-mode.
3. Repeat the above-mentioned tests/measurements on the same test object with an angle beam probe and then with a TR probe (transmitter-receiver probe).
4. Assess and represent the detectability of the discontinuities with the respective test methods.

Learning objectives

• Ultrasonic echography
• Discontinuity
• A-Mode
• Straight beam probe
• Angle beam probe
• Reflection
• Beam angle
• Signal-to-noise ratio