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Industrial radiographic testing using digital and conventional techniques to inspect welds and materials for internal defects with precise, documented results.
Radiographic Testing (RT) passes penetrating radiation — X-rays from a tube or gamma rays from an isotope source (Ir-192, Se-75, Co-60) — through the component onto a detector. Denser, sound metal absorbs more radiation than a void, so internal discontinuities appear as darker or lighter indications on the radiograph, giving a permanent volumetric picture of the weld or casting.
We provide both conventional film radiography and modern digital radiography — Computed Radiography (CR) and Digital Detector Arrays (DR) — chosen for image quality, speed and archiving. All work is carried out under strict radiation-safety controls with a demarcated exclusion zone, dosimetry and a licensed radiation-protection regime.
A radiation source is placed on one side of the weld and a detector (film, imaging plate or digital panel) on the other. As radiation passes through, thicker or denser material attenuates it more, so a cavity, crack or inclusion lets more radiation through and records as a darker area on the image.
Image quality is proven with an Image Quality Indicator (IQI or penetrameter) that must resolve a specified wire or hole size, and geometry — source-to-object distance, focal spot and exposure — is controlled so the radiograph has the required density, contrast and sensitivity.
RT excels at volumetric discontinuities: gas porosity, slag and tungsten inclusions, incomplete penetration, incomplete fusion, undercut, concavity and burn-through, and shrinkage cavities in castings. It leaves a permanent image showing the shape and distribution of the defect through the section.
Because detection depends on a measurable change in absorbed radiation, RT is less reliable for tight, planar cracks lying across the beam than ultrasonics — which is why RT and UT/PAUT are often specified as complementary volumetric methods.
Conventional film radiography gives very high resolution and a legally archivable hard copy, and remains a code baseline. Computed Radiography (CR) uses a reusable phosphor imaging plate scanned into a digital image, cutting consumables and processing chemicals. Digital Detector Arrays (DR) capture the image directly for near-instant results, image processing and easy digital archiving.
We select the technique — source type, energy and detector — for the material and thickness, and can deploy X-ray crawlers for pipeline double-wall shots and panoramic exposures where geometry allows.
Ionising radiation is hazardous, so RT is carried out only by licensed radiographers under a formal radiation-protection programme. A controlled exclusion zone is established and monitored with survey meters and audible dose-rate alarms; every operator wears a dosimeter and pocket alarm and the source is accounted for at all times.
Wherever possible we schedule shots to minimise exposure to other trades, use collimators and the lowest sufficient source strength, and where practical substitute PAUT/TOFD to remove radiation from the worksite entirely.
Film uses radiation-sensitive film developed with chemicals — highest resolution and a permanent hard copy, but slower and consumable-heavy. CR (Computed Radiography) exposes a reusable phosphor plate that is scanned into a digital image. DR (Digital Detector Array) captures the image electronically for near-instant, processable digital results. CR and DR cut chemicals and turnaround time and simplify archiving; film is still specified where its resolution or a hard-copy record is required.
Only within a controlled exclusion zone that is barriered, signed and continuously monitored so no unauthorised person can enter while the source is exposed. That is why RT is often done on back-shift or during breaks. Where continuous parallel work is essential, we favour PAUT/TOFD, use collimated low-energy sources, or plan the geometry to shrink the zone — always under a licensed radiation-protection supervisor.
RT is favoured for volumetric defects — porosity, slag and shrinkage in welds and castings — and where a permanent visual image of the whole weld is wanted for records or client review. Thin sections and complex castings also image well. For tight planar cracks, lack of fusion and thick sections, UT or PAUT is usually more sensitive, so the two are frequently specified together.
Tell us what you need and our engineering team will prepare a tailored proposal.