ASTM E903-12

Standard Test Method for Solar Absorptance, Reflectance, and Transmittance of Materials Using Integrating Spheres

SIGNIFICANCE AND USE
5.1 Solar-energy absorptance, reflectance, and transmittance are important in the performance of all solar energy systems ranging from passive building systems to central receiver power systems. This test method provides a means for determining these values under fixed conditions that represent an average that would be encountered during use of a system in the temperate zone.  
5.2 Solar-energy absorptance, reflectance, and transmittance are important for thermal control of spacecraft and the solar power of extraterrestrial systems. This test method also provides a means for determining these values for extraterrestrial conditions.  
5.3 This test method is designed to provide reproducible data appropriate for comparison of results among laboratories or at different times by the same laboratory and for comparison of data obtained on different materials.  
5.4 This test method has been found practical for smooth materials having both specular and diffuse optical properties. Materials that are textured, inhomogeneous, patterned, or corrugated require special consideration.  
5.4.1 Surface roughness may be introduced by physical or chemical processes, such as pressing, rolling, etching, or deposition of films or chemical layers on materials, resulting in textured surfaces.  
5.4.2 The magnitude of surface roughness with respect to the components of the spectrophotometer and attachments (light beam sizes, sphere apertures, sample holder configuration) can significantly affect the accuracy of measurements using this test method.  
5.4.3 Even if the repeatability, or precision of the measurement of textured materials is good, including repeated measurements at various locations within or orientations of the sample, the different characteristics of different spectrophotometers in different laboratories may result in significant differences in measurement results.  
5.4.4 In the context of 5.4.3, the term ‘significant’ means differences exceeding the calibration or m...
SCOPE
1.1 This test method covers the measurement of spectral absorptance, reflectance, and transmittance of materials using spectrophotometers equipped with integrating spheres.  
1.2 Methods of computing solar weighted properties from the measured spectral values are specified.  
1.3 This test method is applicable to materials having both specular and diffuse optical properties.  
1.4 This test method is applicable to material with applied optical coatings with special consideration for the impact on the textures of the material under test.  
1.5 Transmitting sheet materials that are inhomogeneous, textured, patterned, or corrugated require special considerations with respect to the applicability of this test method. Test Method E1084 may be more appropriate to determine the bulk optical properties of textured or inhomogeneous materials.  
1.6 For homogeneous materials this test method is preferred over Test Method E1084.  
1.7 This test method refers to applications using standard reference solar spectral distributions but may be applied using alternative selected spectra as long as the source and details of the solar spectral distribution and weighting are reported.  
1.8 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 30-Nov-2012
• ICS: 77.140.80 - Iron and steel castings
• Technical Committee: E44 - Solar, Geothermal and Other Alternative Energy Sources
• Drafting Committee: E44.20 - Optical Materials for Solar Applications

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:E903 −12
Standard Test Method for
Solar Absorptance, Reflectance, and Transmittance of
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Materials Using Integrating Spheres
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 of last 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
Ultraviolet and Visible Spectrophotometers
1.1 This test method covers the measurement of spectral
E424 Test Methods for Solar Energy Transmittance and
absorptance, reflectance, and transmittance of materials using
Reflectance (Terrestrial) of Sheet Materials
spectrophotometers equipped with integrating spheres.
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
E971 Practice for Calculation of Photometric Transmittance
1.3 This test method is applicable to materials having both
specular and diffuse optical properties. and Reflectance of Materials to Solar Radiation
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 consideration for the impact on
E1175 Test Method for Determining Solar or Photopic
the textures of the material under test.
Reflectance, Transmittance, andAbsorptance of Materials
1.5 Transmitting 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 respect to the applicability of this test method. 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 TablesforReferenceSolarSpectralIrradiances:Direct
Normal and Hemispherical on 37° Tilted Surface
1.6 For homogeneous materials this test method is preferred
G197 Table for Reference Solar Spectral Distributions: Di-
over Test Method E1084.
rect and Diffuse on 20° Tilted and Vertical Surfaces
1.7 This test method refers to applications using standard
2.2 Other Documents:
reference solar spectral distributions but may be applied using
3
Federal Test Method Standard No. 141, Method 6101
alternative selected spectra as long as the source and details of
4
ASHRAE Standard 74-1988
the solar spectral distribution and weighting are reported.
CIE 38 Radiometric and Photometric Characteristics of Ma-
1.8 This standard does not purport to address all of the 5
terials and their Measurement
safety concerns, if any, associated with its use. It is the 5
CIE 44 Absolute Methods for Reflection Measurement
responsibility of the user of this standard to establish appro- 6
NIST SP 250-48 Spectral Reflectance
priate safety and health practices and determine the applica- 7
NIST SP 250-69 Regular Spectral Transmittance
bility of regulatory limitations prior to use.
3. Terminology
2. Referenced Documents
3.1 The following definitions are consistent with Terminol-
2
2.1 ASTM Standards:
ogy E772.Additional terms appropriate to this test method are
included in Terminology E772.
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This test method is under the jurisdiction of ASTM Committee E44 on Solar,
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Geothermal and OtherAlternative Energy Sources and is the direct responsibility of AvailablefromStandardizationDocuments,OrderDesk,Building4,SectionD,
Subcommittee E44.20 on Glass for Solar Applications. 700 Robbins Ave., Philadelphia, PA 19111-5049, Attn: NPODS.
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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 1996 as E903–96 which was Conditioning Engineers, Inc., 191 Tullie Circle, NE. Atlanta GA 30329.
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withdrawnAugust 2005 and reinstated in December 2012. DOI: 10.1520/E0903-12. Available from U.S. National Committee of the CIE (International Commission
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or on Illumination), C/o Thomas M. Lemons, TLA-Lighting Consultants, Inc., 7 Pond
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM St., Salem, MA 01970, http://www.cie-usnc.org.
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Standards volume information, refer to the standard’s Document Summary page on Available on line at http://www.nist.gov/pml/div685/pub/upload/sp250-48.pdf
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the ASTM website. Available on line at http://www.nist.gov/calibrations/upload/SP250-69.pdf
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