Founding - Radiographic testing - Part 2: Techniques with digital detectors
This European Standard gives specific procedures for industrial X-ray and gamma radiography for discontinuity detection purposes, using NDT (Non-destructive testing) digital X-ray image detectors. This part of EN 12681 specifies the requirements for digital radiographic testing by either computed radiography (CR) or radiography with digital detector arrays (DDA) of castings.
Digital detectors provide a digital grey value image which can be viewed and evaluated using a computer.
NOTE This part of EN 12681 complies with EN 14784-2 for CR. Some clauses and annexes are taken from EN ISO 17636-2.
This part of EN 12681 describes the recommended procedure for detector selection and radiographic practice. Selection of computer, software, monitor, printer and viewing conditions are important but are not the main focus of this standard. The procedure specified in this standard provides the minimum requirements for radiographic practice which permit exposure and acquisition of digital radiographs with equivalent sensitivity for detection of imperfections as film radiography, as specified in Part 1 of this standard.
The requirements on image quality in class A and B testing of Annex A consider the good workmanship quality for general casting applications as also required in Part 1 of this standard for film radiography.
The classes AA and BA reflect the quality requirements of current automated and semi-automated radiographic inspection systems with DDAs (computer based flaw recognition or visual inspection) and mini or micro focus tubes (spot size ≤ 1 mm) with reduced requirements to the unsharpness.
The described procedures are applicable to castings produced by any casting process, especially for steel, cast iron, aluminium, cobalt, copper, magnesium, nickel, titanium, zinc and any alloys of them.
This part of this European Standard does not apply to:
- the testing of welded joints (see EN ISO 17636-2);
- film radiography;
- real time testing with radioscopy.