Ultrasonic Testing (UT) uses ultrasound to conduct examinations and make measurements. A typical UT system consists of a pulser/receiver, a transducer, and a display device. Driven by the pulser, the transducer generates high frequency ultrasound, which propagates through the material in the form of waves. Flaws reflect ultrasound back to the transducer. The reflected wave signal is transformed into an electrical signal by the transducer and is displayed on a screen. Signal travel time can be directly related to the distance that the signal travelled. The reflected signal provides information about the flaw’s location, size and orientation.
Advantages
- Sensitivity to both surface and subsurface discontinuities
- Through-thickness depth of flaw can be measured. This is vital when it comes to consider the significance of the flaw with regard to structural integrit
- Only single-sided access required
- Highly accurate in determining reflector position and estimating size and shape
- Minimal part preparation is required
- Electronic equipment provides instantaneous results
- It has other uses in addition to flaw detection, such as thickness measurement
Applications
TWI’s applications of manual UT are many and varied. It is often used as a follow up to one of the computerised techniques.
Other examples are:
- Checking the quality of welds in pipes used in fatigue test to simulate resonance in steel catenary risers for the offshore oil industry
- Inspection of escalator drive shafts for London Underground
- Measuring plastic coating thickness for Petrobras
For more information, please contact us.
