ČSN EN 12681-2

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 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 this standard. The procedure specified in this standard 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 standard. This standard does not consider radiographic or radioscopic fitness for purpose testing as applied for specific castings based on manufacturer's internal requirements and procedures. 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 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 standard 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. This part of this European Standard 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).