RT Radiographic

Radiographic testing evaluates the density differences produced on a film or digital detector by ionising radiation passed through the material. Where there is a flaw the material thickness is lower, so a darker indication appears in the image.

The aim is to detect internal flaws on a permanent, verifiable image. The great strength of radiography is that the result can later be re-evaluated independently.

• Pressure equipment and pipeline weld seams
• Internal discontinuities in cast parts
• Storage tank welds
• Structural steel butt welds
• Composite and assembly components

NDT has no interval of its own; how often it is applied follows the inspection programme it serves. In manufacturing the governing factor is the coverage required by the product standard and the specification (e.g. a given percentage of welds); in operation it is the asset integrity or risk-based inspection programme.

• Porosity and gas pockets
• Slag and tungsten inclusions
• Lack of penetration and lack of fusion
• Cracks (when suitably oriented to the beam)
• Undercut and root defects
• Thickness variations and assembly deviations

• ISO/IEC 17020
• EN ISO 17636-1
• EN ISO 17636-2
• EN ISO 10675-1
• ISO 19232 series
• ISO 9712

• X-ray tube or gamma source (Ir-192, Se-75, Co-60)
• Radiographic film or digital detector (CR/DR)
• Image quality indicators (IQI / penetrameter)
• Film processing or digital imaging system
• Film viewer and densitometer
• Radiation survey meters and personal dosimeters

1. 1Selection of Method and TechniqueThe type and location of the discontinuity sought and the material properties are assessed to select a suitable method and technique; a written procedure is prepared.
2. 2Verification of Personnel and EquipmentThe level and industrial-sector qualification of the operator under EN ISO 9712 and the calibration records of the equipment are checked.
3. 3Surface PreparationThe inspection surface is prepared as the method requires; coating, rust and contamination directly affect the sensitivity of the method.
4. 4Calibration and Sensitivity VerificationA reference block or control specimen is used to demonstrate that the system can detect the discontinuity sought.
5. 5Performing the InspectionScanning is carried out according to the procedure; indications are recorded and located.
6. 6AssessmentIndications are evaluated against the applicable acceptance standard to determine whether they are defects; they are sized.
7. 7ReportingMethod, technique, equipment, calibration, findings and acceptance criteria are reported together.

Defects are assessed against an acceptance standard such as EN ISO 10675-1, together with the applied quality level. Adequacy of image quality is proven by the finest wire or hole visible on the IQI; a radiograph that does not satisfy the IQI requirement is invalid.

• The inspection body and the personnel's EN ISO 9712 level and sector
• Method and technique applied and the written procedure number
• Part and weld examined, with a location sketch
• Equipment, consumables and calibration records
• Surface condition and inspection conditions
• Indications recorded, with their location and size
• Acceptance standard applied and the result of the evaluation
• Accept / reject decision

Non-destructive testing is carried out as an accredited inspection activity under ISO/IEC 17020. The second decisive factor in NDT is personnel qualification: the operator must be certified under EN ISO 9712 for the method, level and industrial sector concerned. An examination performed with a method outside the scope of that certificate is not valid. EUROLAB holds internationally recognised accreditation under ISO/IEC 17020, granted by accreditation bodies that are signatories to the ILAC mutual recognition arrangement.

• VT Visual
• PT Penetrant
• MT Magnetic Particle
• UT Ultrasonic
• ET Eddy Current
• PAUT
• TOFD
• Leak Testing