1.1 本试验方法包括测量材料和表面的绝对总太阳或明视反射率、透射率或吸收率。尽管有几种适用的试验方法用于测定材料的光学特性，但它们通常仅适用于平坦、均匀、各向同性的试样。图案化、纹理化、波纹化或尺寸异常的材料无法使用传统的分光光度法准确测量，或者需要多次测量才能获得相关的光学值。本试验方法的目的是提供一种对空间非均匀材料进行精确光学特性测量的方法。 1.2 本试验方法适用于同时具有镜面和漫反射光学特性的材料的大样本。它特别适合测量不透明材料的反射率以及半透明材料（包括波纹纤维）的反射率和透射率- 增强塑料、复合透明和半透明样品、纹理严重的表面以及非均质材料，如编织木材、百叶窗、窗帘等。 1.3 以国际单位表示的数值应视为标准值。括号中给出的值仅供参考。 1.4 本标准并不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。 （有关具体安全危险，请参见 注释1 .) 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）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》中确立的国际公认标准化原则制定的。 =====意义和用途====== 5.1 当测量非均匀材料时，为了克服传统分光光度测量技术的不足，可以使用大型积分球。 4. , 5. 由于与被测材料的差异相比，此类球体中使用的光束较大，因此在单个实验测定中，被测样品的非各向同性本质基本上是平均的，或是从测量中综合出来的。 5.2 可使用单独定制的单功能球体测量太阳和明视光学特性，以测量任一透射率 5. 或者反射率，或者可以用一个用于测量透射率和反射率的多功能球体来测量。 4. 5.3 多功能球体用于测量定向半球和定向半球的总太阳透过率- 定向模式。太阳吸收率可以在一次测量中评估为1减去定向半球反射率和透射率之和。当球体中心的样品由其边缘支撑时，反射率和透射率之和可以作为入射角的函数来测量。太阳吸收率为1减去测量的吸收率加上透射率。

1.1 This test method covers the measurement of the absolute total solar or photopic reflectance, transmittance, or absorptance of materials and surfaces. Although there are several applicable test methods employed for determining the optical properties of materials, they are generally useful only for flat, homogeneous, isotropic specimens. Materials that are patterned, textured, corrugated, or are of unusual size cannot be measured accurately using conventional spectrophotometric techniques, or require numerous measurements to obtain a relevant optical value. The purpose of this test method is to provide a means for making accurate optical property measurements of spatially nonuniform materials. 1.2 This test method is applicable to large specimens of materials having both specular and diffuse optical properties. It is particularly suited to the measurement of the reflectance of opaque materials and the reflectance and transmittance of semitransparent materials including corrugated fiber-reinforced plastic, composite transparent and translucent samples, heavily textured surfaces, and nonhomogeneous materials such as woven wood, window blinds, draperies, etc. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.4 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. (For specific safety hazards, see Note 1 .) 1.5 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 To overcome the inadequacies of conventional spectrophotometric measurement techniques when nonhomogeneous materials are measured, a large integrating sphere may be used. 4 , 5 Since the beam employed in such spheres is large in comparison to the disparaties of the materials being tested, the nonisotropic nature of the specimen being measured is essentially averaged, or integrated out of the measurement, in a single experimental determination. 5.2 Solar and photopic optical properties may be measured either with monofunctional spheres individually tailored for the measurement of either transmittance 5 or reflectance, or may be measured with a single multifunctional sphere that is employed to measure both transmittance and reflectance. 4 5.3 A multifunctional sphere is used for making total solar transmittance measurements in both a directional-hemispherical and a directional-directional mode. The solar absorptance can be evaluated in a single measurement as one minus the sum of the directional hemispherical reflectance and transmittance. When a sample at the center of the sphere is supported by its rim, the sum of the reflectance and transmittance can be measured as a function of the angle of incidence. The solar absorptance is then one minus the measured absorptance plus transmittance.