Designation: E903 - 12 Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres1 This standard is issued under the fixed designation E903; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year oflast revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon ()indicates an editorial change since the last revision or reapproval. 1. Scope E275 Practice for Describing and Measuring Performance of 1.1 This test method covers the measurement of spectral Ultraviolet and Visible Spectrophotometers E424 Test Methods for Solar Energy Transmittance and absorptance,reflectance,andtransmittanceofmaterials using spectrophotometers equipped with integrating spheres. Reflectance (Terrestrial) of Sheet Materials E490 Standard Solar Constant and Zero Air Mass Solar 1.2 Methods of computing solar weighted properties from Spectral Irradiance Tables the measured spectral values are specified. E772 Terminology of Solar Energy Conversion 1.3 This test method is applicable to materials having both E971 Practice for Calculation of Photometric Transmittance specular and diffuse optical properties. E1084 Test Method for Solar Transmittance (Terrestrial) of 1.4 This test method is applicable to material with applied Sheet Materials Using Sunlight optical coatings with special considerationforthe impacton E1175 Test Method for Determining Solar or Photopic the textures of the material under test. Reflectance, Transmittance, and Absorptance of Materials 1.5Transmitting sheet materials that are inhomogeneous, Using a Large Diameter Integrating Sphere textured, patterned, or corrugated require special consider- E2554 Practice for Estimating and Monitoring the Uncer- ations with respecttothe applicability ofthis testmethod.Test tainty of Test Results of a Test Method Using Control Method E1084 may be more appropriate to determine the bulk Chart Techniques optical properties of textured or inhomogeneous materials. G173 Tables for Reference Solar Spectral Irradiances: Direct 1.6 For homogeneous materials this test method is preferred Normal and Hemispherical on 37° Tilted Surface over Test Method E1084. G197 Table for Reference Solar Spectral Distributions: Di- 1.7 This test method refers to applications using standard rect and Diffuse on 20° Tilted and Vertical Surfaces 2.2 Other Documents: reference solar spectral distributions but may be applied using Federal Test Method Standard No. 141, Method 61013 alternative selected spectra as long as the source and details of the solar spectral distribution and weighting are reported. ASHRAE Standard74-19884 CIE38Radiometric and Photometric Characteristics of Ma- 1.8 This standard does not purport to address all of the terials and their Measurements safety concerns, if any, associated with its use. It is the CIE 44 Absolute Methods for Reflection Measurements responsibility of the user of this standard to establish appro- NIST SP 250-48 Spectral Reflectance6 priate safety and health practices and determine the applica- NIST SP 250-69 Regular Spectral Transmittance7 bility of regulatory limitations prior to use. 3. Terminology 2. Referenced Documents 3.1Thefollowing definitions are consistent with Terminol- 2.1ASTMStandards.2 ogy E772. Additional terms appropriate to this test method are included in Terminology E772. This test method is under the jurisdiction of ASTM Committee E44 on Solar, Geothermal and Other Alternative Energy Sources and is the direct responsibility of 3 Available from Standardization Documents, Order Desk, Building 4, Section D Subcommittee E44.20 on Glass for Solar Applications. 700 Robbins Ave., Philadelphia, PA 19111-5049, Attn: NPODS. Current edition approved Dec. 1, 2012. Published December 2012. Originally + Available from American Society of Heating, Refrigeration, and Air- approved in 1982. Last previous edition approved in 1