1.1 本试验方法描述了适用于测量大、厚或弯曲透明部件（包括已安装部件）透射率的仪器和程序。该测试方法仅限于相对于波长相对中性的透明胶片（颜色不太浓）。 1.2 由于透射率（透射系数）是两个亮度值的比率，因此它没有单位。本试验方法中间步骤中记录的亮度单位并不重要；只要使用一致，任何公认的亮度单位（例如，每平方米英尺朗伯或坎德拉）都可以使用。 1.3 本标准并非旨在解决与其使用相关的所有安全问题（如有）。 本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.4 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 意义- 该试验方法提供了一种测量现场零件（已安装在飞机上）以及物理上难以使用试验方法测量的大、厚或弯曲零件透射率的方法 2003年1月 。 5.2 使用- 此测试方法可用于任何透明部件。它主要用于安装前或安装后的大型、弯曲或厚部件（例如，飞机上的挡风玻璃）。

1.1 This test method describes an apparatus and procedure that is suitable for measuring the transmissivity of large, thick, or curved transparent parts including parts already installed. This test method is limited to transparencies that are relatively neutral with respect to wavelength (not highly colored). 1.2 Since the transmissivity (transmission coefficient) is a ratio of two luminance values, it has no units. The units of luminance recorded in the intermediate steps of this test method are not critical; any recognized units of luminance (for example, foot-lamberts or candelas per square metre) are acceptable for use, as long as use is consistent. 1.3 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. 1.4 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. ====== Significance And Use ====== 5.1 Significance— This test method provides a means to measure the transmissivity of parts in the field (already installed on aircraft) and of large, thick or curved parts physically difficult to measure using Test Method D1003 . 5.2 Use— This test method is acceptable for use on any transparent part. It is primarily intended for use on large, curved, or thick parts either pre- or post-installation (for example, windscreens on aircraft).