【国外标准】 Standard Digital Reference Images for Magnesium Castings

4.1 These digital reference images are intended for reference only, but are so designed that acceptance standards, which may be developed for particular requirements, can be specified in terms of these digital reference images. The illustrations are digital images prepared from castings that were produced under conditions designed to develop the discontinuities. The images of the 1/4 in. (6.4 mm) castings are intended to be used in the thickness range up to and including 1/2 in. (12.7 mm). The images of the 3/4 in. (19.1 mm) castings are intended to be used in the thickness range of over 1/2 in. (12.7 mm), up to and including 2 in. (50.8 mm).4.2 Image Deterioration—Many conditions can affect the appearance and functionality of digital reference images. For example, electrical interference, hardware incompatibilities, and corrupted files or drivers may affect their appearance. The ASTM E2002 line pair gauges located in the lower right hand corner of each digital reference can be used as an aid to detect image deterioration by comparing the measured resolution using the gauges to the resolution stated on the digital reference image. Do not use the digital reference images if their appearance has been adversely affected such that the interpretation and use of the images could be influenced.4.3 Agreement should be reached between cognizant engineering organization and the supplier that the system used by the supplier is capable of detecting and classifying the required discontinuities.1.1 These digital reference images illustrate the types and degrees of discontinuities that may be found in magnesium-alloy castings. The castings illustrated are in thicknesses of 1/4 in. (6 mm) and 3/4 in. (19.1 mm).1.2 All areas of this standard may be open to agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These items should be addressed in the purchase order or the contract.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 These digital reference images are not intended to illustrate the types and degrees of discontinuities found in magnesium-alloy castings when performing film radiography. If performing film radiography of magnesium-alloy castings, refer to Reference Radiographs E155.1.5 Only licensed copies of the software and images shall be utilized for production examination. A copy of the ASTM/User license agreement shall be kept on file for audit purposes.NOTE 1: The set of digital reference images consists of 14 digital files, software to load the desired format and specific instructions on the loading process. The 14 reference images illustrate eight grades of severity and contain an image of a step wedge and two duplex wire gauges.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.