意义及用途
4.1 This practice is used to determine the effects of ultraviolet light or ultraviolet light and water on adhesive bonded joints under controlled but artificial conditions. The results of this practice can be used to compare the relative durability of several adhesives under specific laboratory UV exposure.
4.2 This practice is not intended to determine the lifetime prediction of the adhesive in use. It is only used to determine the relative durability between different adhesives.
4.3 Due to the different spectral irradiance of the lamp, the results obtained may vary depending on the light source (xenon arc or fluorescent ultraviolet). Adhesives should not be compared based on their performance under different types of light sources.
4.4 When operating conditions vary within the scope of a given method, the results obtained may vary. Results may also vary when exposing instruments made by different manufacturers. Materials can only be compared if they are tested simultaneously in the same instrument. Be sure to accurately report operating conditions.
4.5 The type of transparent adhesive used and the UV transmittance characteristics have a significant impact on the rate and type of degradation of the adhesive under test. Adhesives can only be compared when tested on the same type (recommended is the same batch) of transparent adhesives with the same UV transmittance.
4.6 This approach is not intended to determine the impact of atmospheric pollutants, biological organisms, salts or freeze-thaw cycles.
ASTM D904-2021 Fluorescent Ultraviolet (see Method A) or xenon Arc Sources (see Method B)
半径
1.1 This practice covers the fundamentals and operating procedures for ultraviolet (紫外线) 老化 (with or without water) of adhesive joints with at least one glass or transparent adhesive using fluorescent UV (see Method A) or xenon arc light sources (see Method B).
1.2 This practice is limited to equipment that acquires, measures and controls aging conditions, and exposure procedures. 样品制备, strength, test conditions, and evaluation of results are described in other ASTM test methods or specifications.
1.3 Values expressed in SI units shall be treated as standard values. 本标准不包含其他计量单位.
1.4 本标准并非旨在解决所有安全问题, 如果有的话, 与其使用相关. 本标准的使用者有责任建立适当的安全机制, 健康和环境实践，并在使用前确定监管限制的适用性.
1.5 本国际标准基于《关于制定国际标准的原则的决定》中确立的国际公认的标准化原则, Guidelines and Recommendations issued by the WTO Committee on Technical Barriers to Trade.