ASTM C1864-17

5.1 The solar reflectance of a DRM depends on the solar incidence angle. This method is intended to provide solar reflectance values for DRM roofing products.

1.1 This test method covers a technique for determining the solar reflectance of a directionally reflective material using a commercial portable solar reflectometer, including but not limited to roofing materials with granules or surface design that results in angularly dependent reflectance. The purpose of the method is to evaluate the seasonal and annual solar reflectances of a directionally reflective roofing product.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

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.