Ultrasonic Testing (UT)
Detecting hidden flaws inside components using sound waves.
What Is Ultrasonic Testing?
Ultrasonic Testing (UT) is a non-destructive testing method that uses high-frequency sound waves to detect internal flaws and measure material properties. If you need to see inside a component without cutting it open — whether for weld inspection, thickness surveys, or corrosion mapping — UT is the method that delivers the answers.
Internal flaws invisible to surface methods do not stay dormant. Under load or pressure, they propagate — and the first sign of their existence can be unexpected failure. A subsurface crack in a structural weld, undetected corrosion thinning a pressure vessel wall, or a hidden inclusion in a forging can all lead to catastrophic consequences. UT finds these defects before they find you.
Clearscope's PCN/ASNT-certified technicians carry out ultrasonic inspections across manufacturing, construction, and energy applications. Whether it is a single weld assessment or a programme-wide thickness survey, every inspection is documented with full traceability and reported to the applicable standard.
How UT Works
Four stages from couplant application through to signal analysis and defect characterisation.
Couplant Applied to Surface
A gel or liquid couplant is applied to the test surface to eliminate air gaps and ensure efficient sound wave transmission between the transducer and the material.
Transducer Sends Ultrasonic Pulse
The transducer generates high-frequency sound waves (typically 0.5 to 15 MHz) that travel through the material being inspected.
Sound Waves Reflect from Flaws
When the ultrasonic pulse encounters an internal discontinuity — a crack, void, or inclusion — part of the sound energy is reflected back toward the transducer.
Return Signal Analysed on Screen
The reflected signals are displayed on a screen as peaks. The position and amplitude of these peaks indicate the depth, size, and nature of any internal flaws.
Defects Detected
Internal cracks
Hidden fractures within the material structure
Porosity
Gas pockets trapped during solidification
Incomplete weld penetration
Insufficient fusion at the weld root
Slag inclusions
Non-metallic material trapped in the weld
Voids
Empty spaces within the material
Misalignment
Offset or displaced joint components
Limitations
Requires couplant (gel) for contact between transducer and surface
Operator skill and certification are critical for accurate interpretation
Complex geometries can create signal noise and interpretation challenges
How Clearscope Helps
What we deliver — specific, practical, and built to hold up under audit.
Contact UT
Standard contact ultrasonic testing for weld inspection, flaw detection, and material assessment using calibrated equipment and certified technicians.
Thickness Gauging
Ultrasonic thickness measurement for corrosion monitoring, remaining life assessment, and wall thickness surveys across pipes, vessels, and structural members.
Weld Inspection
Volumetric weld inspection to EN ISO 17640 and ASME Section V — detecting internal flaws that surface methods cannot reach.
Corrosion Mapping
Systematic thickness surveys that map wall loss across vessels, tanks, and pipework to identify thinning patterns and prioritise maintenance.
TOFD & PAUT
Time of Flight Diffraction and Phased Array UT for complex geometry, accurate flaw sizing, and advanced inspection requirements.
Need ultrasonic testing?
Talk to our certified technicians about your internal inspection and thickness measurement requirements.