ASTM G197-08(2012)
Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20deg; Tilted and Vertical Surfaces

Standard No.

ASTM G197-08(2012)

Release Date

2008

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM G197-14

Latest

ASTM G197-14(2021)

Scope

5. Significance and UseTop Bottom

5.1 This standard does not purport to address the mean spectral irradiance incident on tilted or vertical fenestration or building-integrated systems over a day, a season, or a year. The spectral irradiance distributions have been chosen to represent a reasonable near-upper limit for solar radiation when these systems are exposed to clear-sky conditions similar to those used to calculate solar heat loads of buildings. The diffuse spectral irradiance distributions can also be used to represent conditions when these systems are shaded from the direct sun.

5.2 Absorptance, reflectance, and transmittance of solar radiation are important factors in studies of light transmission through semi-transparent plates. These properties are normally functions of wavelength, which require that the spectral distribution of the solar flux be known before the solar-weighted property can be calculated.

5.3 To compare the relative performance of competitive products by computerized simulations, or to compare the performance of products subjected to experimental tests in laboratory conditions, a reference standard solar spectral distribution for both direct and diffuse irradiance is desirable.

5.4 The table provides appropriate standard spectral irradiance distributions for determining the relative optical performance of semi-transparent materials and other systems. The table may be used to evaluate components and materials for the purpose of solar simulation where the direct and the diffuse spectral solar irradiances are needed separately.

FIG. 1 Plot of Direct Spectral Irradiance on 20?? Tilted Sun-Facing Surface (Dotted Line) and 90?? Tilted Sun-Facing Surface (Solid Line) Computed Using SMARTS Version 2.9.2 Model with Input File in Tables 1 and 2

FIG. 2 Plot of Diffuse Spectral Irradiance on 20?? Tilted Sun-Facing Surface (Dotted Line) and 90?? Tilted Sun-Facing Surface (Solid Line) Computed Using SMARTS Version 2.9.2 Model with Input File in Tables 1 and 2

ASTM G197-08(2012) history

• 2021 ASTM G197-14(2021) Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20° Tilted and Vertical Surfaces
• 2014 ASTM G197-14 Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20° Tilted and Vertical Surfaces
• 2008 ASTM G197-08(2012) Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20deg; Tilted and Vertical Surfaces
• 2008 ASTM G197-08 Standard Table for Reference Solar Spectral Distributions: Direct and Diffuse on 20x00B0; Tilted and Vertical Surfaces