【国外标准】 Standard Practice for Radioscopic Examination of Weldments

This test method covers a uniform procedure for radioscopic examination of weldments. Requirements expressed in this test method are intended to control the quality of the radioscopic images and are not intended for controlling acceptability or quality of welds. It applies only to the use of equipment for radioscopic examination in which the image is finally presented on a television monitor for operator evaluation. The examination may be recorded for later review. It does not apply to fully automated systems where evaluation is automatically performed by computer. Unless otherwise specified by the applicable job order or contract, radioscopic examination shall be performed in accordance with a written procedure which includes: material and thickness range to be examined; equipment to be used, including specifications of source parameters and imaging equipment parameters; examination geometry, including source-to-object distance, object-to-detector-distance and orientation; image quality indicator designation and placement; test-object scan plan, indicating the range of motions and manipulation speeds through which the test object shall be manipulated in order to ensure satisfactory results; image-processing parameters; image-display parameters; and image storage.1.1 This practice covers a uniform procedure for radioscopic examination of weldments. Requirements expressed in this practice are intended to control the quality of the radioscopic images and are not intended for controlling acceptability or quality of welds.1.2 This practice applies only to the use of equipment for radioscopic examination in which the image is finally presented on a display screen (monitor) for operator evaluation. The examination may be recorded for later review. It does not apply to fully automated systems where evaluation is automatically performed by computer.1.3 The radioscopic extent, the quality level, and the acceptance criteria to be applied shall be specified in the contract, purchase order, product specification, or drawings.1.4 This practice can be used for the detection of discontinuities. This practice also facilitates the examination of a weld from several directions, such as perpendicular to the weld surface and along both weld bevel angles. The radioscopic techniques described in this practice provide adequate assurance for defect detectability; however, it is recognized that, for special applications, specific techniques using more stringent requirements may be needed to provide additional detection capability. The use of specific radioscopic techniques shall be agreed upon between purchaser and supplier.1.5 Units—The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.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. Specific precautionary statements are given in Section 7.1.7 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.