ASTM E1084-86(2003)
(Test Method)Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight
Standard Test Method for Solar Transmittance (Terrestrial) of Sheet Materials Using Sunlight
SIGNIFICANCE AND USE
Solar transmittance is an important factor in the admission of energy through fenestration, collector glazing, and protective envelopes. This test method provides a means of measuring this factor under fixed conditions. While the data may be of assistance to designers in the selection and specification of glazing materials, the solar transmittance is not sufficient to define the rate of net heat transfer without information on other important factors.
This test method has been found practical for both transparent and translucent materials, as well as for those with transmittance reduced by highly reflective coatings. This test method is particularly applicable to the measurement of transmittance of inhomogeneous, fiber reinforced, patterned, or corrugated materials since the transmittance is averaged over a large area.
This test method may be used to measure transmittance of glazing materials at angles up to 60° off normal incidence.
Note 1—A technique similar to the one described but using a pyrheliometer has been used for the measurement of specular solar reflectance; however, there is insufficient experience with this technique for standardization at present.
SCOPE
1.1 This test method covers the measurement of solar transmittance (terrestrial) of materials in sheet form by using a pyranometer, an enclosure, and the sun as the energy source.
1.2 This test method also allows measurement of solar transmittance at angles other than normal incidence.
1.3 This test method is applicable to sheet materials that are transparent, translucent, textured, or patterned.
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Designation:E1084–86 (Reapproved 2003)
Standard Test Method for
Solar Transmittance (Terrestrial) of Sheet Materials Using
1
Sunlight
This standard is issued under the fixed designation E1084; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2.1 solar flux, n—the total radiation from the sun, both
direct and diffuse.
1.1 This test method covers the measurement of solar
transmittance (terrestrial) of materials in sheet form by using a
4. Summary of Test Method
pyranometer, an enclosure, and the sun as the energy source.
4.1 Usingapyranometertomeasurethesolarirradiance,the
1.2 This test method also allows measurement of solar
test specimen is inserted in the path of the rays from the sun to
transmittance at angles other than normal incidence.
the pyranometer. An enclosure with a nonreflecting bottom is
1.3 This test method is applicable to sheet materials that are
used to avoid measuring flux from around the edges of the
transparent, translucent, textured, or patterned.
specimen or from multiple reflections between the box and the
1.4 This standard does not purport to address all of the
specimen. The transmittance is the ratio of the flux measured
safety concerns, if any, associated with its use. It is the
withthespecimeninthelightpathtothefluxmeasuredwithout
responsibility of the user of this standard to establish appro-
the specimen in the path.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents 5.1 Solar transmittance is an important factor in the admis-
sion of energy through fenestration, collector glazing, and
2.1 ASTM Standards:
2
protective envelopes. This test method provides a means of
E284 Terminology of Appearance
3 measuring this factor under fixed conditions. While the data
E772 Terminology Relating to Solar Energy Conversion
may be of assistance to designers in the selection and specifi-
2.2 Other Document:
4 cation of glazing materials, the solar transmittance is not
ASHRAE Handbook of Fundamentals
sufficient to define the rate of net heat transfer without
3. Terminology information on other important factors.
5.2 This test method has been found practical for both
3.1 Definitions:
transparent and translucent materials, as well as for those with
3.1.1 pyranometer, n—a radiometer used to measure the
transmittance reduced by highly reflective coatings. This test
total solar radiant energy incident upon a surface per unit time
method is particularly applicable to the measurement of
per unit area. This energy includes the direct radiant energy,
transmittanceofinhomogeneous,fiberreinforced,patterned,or
diffuse radiant energy, and reflected radiant energy from the
corrugated materials since the transmittance is averaged over a
background.
large area.
3.1.2 solar reflectance, n—the ratio of reflected to incident
5.3 This test method may be used to measure transmittance
solar flux.
of glazing materials at angles up to 60° off normal incidence.
3.1.3 solar transmittance, n—the ratio of transmitted to
incident solar flux.
NOTE 1—A technique similar to the one described but using a pyrhe-
3.2 Definitions of Terms Specific to This Standard:
liometer has been used for the measurement of specular solar reflectance;
however, there is insufficient experience with this technique for standard-
ization at present.
1
These test methods are under the jurisdiction of ASTM Committee E44 on
Solar, Geothermal, and Other Alternative Energy Sources and is the direct
6. Apparatus
responsibility of Subcommittee E44.05 on Solar Heating and Cooling Subsystems
6.1 Enclosure—The required apparatus is a box capable of
and Systems.
Current edition approved Feb. 21, 1986. Published April 1986. Originally
supporting a 0.60 m (24 in.) square specimen. The box shall
approved in 1986. Last previous edition approved in 1996 as E1084–86(1996)
have a square, clear aperture of no less than 0.50 m by 0.50 m
2
Annual Book of ASTM Standards, Vol 06.01.
(20 in. by 20 in.). The enclosure shall have provisions to hold
3
Annual Book of ASTM Standards, Vol 12.02.
4
specimens planar across the aperture with the additional
Available from American Society of Heating, Refrigerating, and Air Condi-
tioning Engineers, 1791 Tullie Circle N.E., Atlanta, GA 30329.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E1084–86 (2003)
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