【国外标准】 Standard Test Method for Scanning Electron Microscope (SEM) Analysis of Metallic Surface Condition for Gas Distribution System Components (Withdrawn 2023)

4.1 The purpose of this test method is to define a procedure for testing components being considered for installation into a high-purity gas distribution system. Application of this test method is expected to yield comparable data among components tested for purposes of qualification for this installation.1.1 This test method covers the testing of interior surfaces of components such as tubing, fittings, and valves for surface morphology.1.2 This test method applies to all surfaces of tubing, connectors, regulators, valves, and any metal component, regardless of size.1.3 Limitations: 1.3.1 This methodology assumes a SEM operator skill level typically achieved over a 12-month period.1.3.2 This test method shall be limited to the assessment of pits, stringer, tears, grooves, scratches, inclusions, stepped grain boundaries, and other surface anomalies. However, stains and particles that may be produced during specimen preparation should be excluded in the assessment of anomalies.1.4 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.1.5 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 hazard statements are given in Section 6.1.6 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.