Automated Ultrasonic Testing (AUT)
AUT is the use of mechanized scanners with encoded position to perform ultrasonic inspection (typically PAUT and/or TOFD) with consistent coverage, full data capture, and repeatable scan plans, widely used for pipeline girth welds.
Definition
Automated Ultrasonic Testing (AUT) employs mechanized scanners — usually band-driven for pipeline girth welds — that carry one or more PAUT and TOFD probes around the weld at a controlled speed. Position is recorded by an encoder, and full waveform data are captured for every position.
Technical Context
AUT replaces radiography on many pipeline construction projects, achieving higher inspection speed and zero radiation exposure. Acceptance is generally per API 1163 and ISO 13588 for the system, with weld acceptance per the construction code.
When It Is Used
- Pipeline girth-weld inspection in lay barges and onshore spreads
- Heavy-wall vessel and nozzle weld inspection
- In-service crack monitoring
How it works
Ultrasonic examination performed with mechanised probe motion and encoded position, so every A-scan is stored against the coordinate where it was captured rather than being watched live and discarded.
What it finds
The same flaws as manual ultrasonics, but with coverage that can be demonstrated afterwards and data that can be re-analysed without returning to site. Girth weld inspection and corrosion mapping are its established uses.
What it will not find
Nothing that manual UT would catch by physics — the limits of orientation, attenuation and near-surface resolution are unchanged. What changes is repeatability and evidence, not detection capability.
How it is actually done
Scanner tracking, encoder calibration and consistent couplant delivery are the practical constraints. Zone discrimination setups for girth welds are built around the weld bevel geometry, so a change in bevel invalidates the setup.
Governing codes and standards
ASME Section V Article 4 with the relevant appendices; ISO 13588 for phased array; API 1104 Annex on ultrasonic examination for pipeline girth welds where mechanised UT substitutes for radiography.
Where it goes wrong
Assuming an encoded scan proves coverage. It proves where the probe went — coverage of the volume of interest additionally requires the beam angles and focal laws to have interrogated that volume, which is a setup question, not a scanning one.
Where Automated Ultrasonic Testing fits in an inspection programme
A term is only useful when it connects to a decision. Automated Ultrasonic Testing appears in written procedures, in technique sheets, and in the records an owner or accreditation body reviews afterwards — which means the way it is defined in your documentation has to match the way it is applied on site. Where the two drift apart, audits find it. Atlantis writes and reviews procedures against the governing codes, trains inspection personnel to apply them, and builds the record-keeping that makes the evidence retrievable years later. Procedure development and code consulting · NDT training and certification · Ask us about your programme.
Related terms
- Phased Array Ultrasonic Testing (PAUT) — PAUT is an advanced ultrasonic technique using a multi-element transducer (16–256 elements) with electronic beam steering and focusing, producing sectorial, linear, and compound scans for superior weld inspection and defect characterization.
- Time-of-Flight Diffraction (TOFD) — TOFD is an advanced UT technique using two angled probes in pitch-catch arrangement to detect and accurately size defects from the time of arrival of diffracted tip signals, achieving height-sizing accuracy of ±0.5 mm.
- ISO 13588 Phased Array Ultrasonic Testing — ISO 13588 is the international standard for automated and semi-automated phased array ultrasonic testing of fusion welds, defining technique levels, scan plan, calibration, and characterization requirements for PAUT.
Further reading
automated ut aut systems complete overview · automated ultrasonic testing systems overview benefits
More method terms
Ultrasonic Testing · Radiographic Testing · Magnetic Particle Testing · Penetrant Testing · Eddy Current Testing · Visual Testing · Acoustic Emission Testing · Leak Testing · Thermography / Infrared Testing · Microwave Testing
Where this comes up in practice
Terms like this one appear in three places that matter commercially: the written practice that governs how your personnel are qualified, the procedures and technique sheets that define how an examination is actually performed, and the evidence an auditor or client asks for when they want to know why an inspection was accepted. Getting the terminology right is the easy part; being able to produce the qualification record, the calibration traceability and the procedure revision that applied on the day of the inspection is the part that decides audits.
Atlantis NDT provides NDT training and certification against ASNT SNT-TC-1A and ISO 9712, ASNT Level III consulting for written practices and procedure approval, inspection management software that holds qualification, calibration and procedure-revision evidence in recoverable form, and an asset integrity platform that binds inspection results to the asset they describe. Browse the full NDT glossary or ask a Level III directly.