What is BS EN 12681-2- Radiographic testing through digital detectors about?
BS EN 12681-2 is a safety standard on radiographic testing. BS EN 12681-2 gives specific procedures for industrial X-ray and gamma radiography for discontinuity detection purposes, using NDT (Non-destructive testing) digital X-ray image detectors. BS EN 12681-2 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 that can be viewed and evaluated using a computer. BS EN 12681-2 also specifies 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 BS EN 12681-2.
The procedure specified in BS EN 12681-2 provides the minimum requirements for radiographic practice which permit exposure and acquisition of digital images with equivalent sensitivity for detection of imperfections as film radiography, as specified in Part 1 of this series. 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 series for film radiography.
The classes AA and BA reflect the quality requirements of current automated and semi-automated radiographic testing systems with DDAs and computer or operator-based image evaluation, and mini or micro focus tubes (spot size ≤ 1 mm) with reduced requirements to the unsharpness, but unchanged requirements to contrast sensitivity as also required in Part 1 of this series for film radiography. The specified procedures are applicable to castings produced by any casting process, especially for steels, cast irons, aluminium, cobalt, copper, magnesium, nickel, titanium, zinc, and any alloys of them.
Note 1: BS EN 12681-2 complies with EN 14784–2 for CR. Some clauses and annexes are taken from EN ISO 17636-2.
Note 2: BS EN 12681-2 does not consider radiographic or radioscopic fitness for purpose testing as applied for specific castings based on the manufacturer’s internal requirements and procedures.
Note 3: BS EN 12681-2 does not apply to:
- The testing of welded joints (see EN ISO 17636-2)
- Film radiography (see EN 12681-1:2017)
- Real time testing with radioscopy (see EN 13068-1; radioscopy with image intensifiers)
Who is BS EN 12681-2- Radiographic testing through digital detectors for?
BS EN 12681-2 on radiographic testing is relevant to:
- Testing authorities of radiography
- Radiography engineers
- NDT personnel
- Manufacturers of radiographic testing machines
Why should you use BS EN 12681-2- Radiographic testing through digital detectors?
Radiography is used to detect internal discontinuities in a casting.
The discontinuities can be gas holes, non-metallic inclusions, shrinkage, cracks, inserts or chills, or inclusions that have lower or higher densities than the parent metal.
The techniques for automated DDA based testing are divided into two classes:
- Class AA: Basic automated techniques
- Class BA: Improved automated technique
Overall, BS EN 12681-2 is helpful as it assists the user with digital detector array system which is an electronic device converting ionizing or penetrating radiation into a discrete array of analogue signals which are subsequently digitized and transferred to a computer for display as a digital image corresponding to the radiologic energy pattern imparted upon the input region of the device.
What’s changed since the last update?
Together with BS EN 12681-1:2017 BS EN 12681-2:2017 supersedes BS EN 12681:2003, which is withdrawn.
Within its programme of work, Technical Committee CEN/TC 190 requested CEN/TC 190/WG 10
“Testing for inner discontinuities”:
- To revise EN 12681:2003 into EN 12681-1, Founding — Radiographic testing — Part 1: Film techniques
- And the preparation of a further standard EN 12681-2, Founding — Radiographic testing — Part 2: Techniques with digital detectors
