Also known as: TOFD.
How it works
A transmitter sends a wide beam across the weld and a receiver on the other side records everything that arrives: a lateral wave along the surface, the back-wall reflection, and between them the low-amplitude waves diffracted from the upper and lower tips of any flaw. Because the arrival time of a tip signal depends only on its depth, the through-wall height of a flaw can be measured to within about a millimetre.
Where it fits
TOFD is a screening and sizing tool for welds in thick pressure vessels, pipelines and offshore structures, and is increasingly used for in-service monitoring of known flaws. It is normally combined with pulse-echo PAUT to cover the near-surface dead zones and to help characterise indications.
TOFD in AMPS
TOFD reports follow the same path as any other method in AMPS: in AMPS, reports are produced from your own Microsoft Word templates through the template engine: job data such as the client, purchase order number, equipment serial numbers, location and dates is filled in automatically, an AI assistant can tidy the wording, the report can be signed in AMPS, and the finished Word file is saved in the job’s report folder in your OneDrive, SharePoint or Google Drive.