1、Designation: E 972 96 (Reapproved 2007)Standard Test Method forSolar Photometric Transmittance of Sheet Materials UsingSunlight1This standard is issued under the fixed designation E 972; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the measurement of solarphotometric transmittance of materials in sheet form.
3、 Solarphotometric transmittance is measured using a photometer(illuminance meter) in an enclosure with the sun and sky as thesource of radiation. The enclosure and method of test isspecified in Test Method E 1175 (or Test Method E 1084).1.2 The purpose of this test method is to specify a photo-metri
4、c sensor to be used with the procedure for measuring thesolar photometric transmittance of sheet materials containinginhomogeneities in their optical properties.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us
5、er of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E 772 Terminology Relating to Solar Energy ConversionE 1084 Test Method for Solar Transmittance (Terrestrial) o
6、fSheet Materials Using SunlightE 1175 Test Method for Determining Solar or PhotopicReflectance, Transmittance, and Absorptance of MaterialsUsing a Large Diameter Integrating Sphere2.2 CIE Standard:Standard Illuminant D6533. Terminology3.1 DefinitionsFor definitions of other terms used in thistest me
7、thod, refer to Terminology E 772.3.1.1 illuminance, nluminous irradiance.3.1.2 luminous (photometric), adjreferring to a radiant(or radiometric) quantity, indicates the weighted average of thespectral radiometric quantity, with the photopic spectral lumi-nous efficiency function (see Annex A1) being
8、 the weightingfunction.3.1.3 radiant flux, F =dQ/dtWatt (W), npower emit-ted, transferred, or received in the form of electromagneticwaves or photons. See radiometric properties and quantities.3.1.4 reflectance, r, Fr/Fi, nthe ratio of the reflected fluxto the incident flux.3.1.5 solar irradiance at
9、 a point of a surface, Es=dF/dA,nthe quotient of the solar flux incident on an element of asurface containing the point, by the area of that element,measured in watts per square metre.3.1.5.1 DiscussionMeasured values of transmittance andreflectance depend upon angle of incidence, solid angles ofinc
10、idence and of transmission and reflection, the method ofmeasurement of the reflected or transmitted flux, and thespectral composition of the incident flux. Because of thisdependence, complete information on the technique and con-ditions of measurement should be specified.3.1.6 solar, adj(1) referrin
11、g to a radiometric term, indi-cates that the quantity has the sun as a source or is character-istic of the sun. (2) referring to an optical property, indicatesthe weighted average of the spectral optical property, with thesolar spectral irradiance Eslused as the weighting function.3.1.7 spectral, ad
12、j(1) for dimensionless optical proper-ties, indicates that the property was evaluated at a specificwavelength, l, within a small wavelength interval, Dl about l,symbol wavelength in parentheses, as L (350 nm, 3500 ), oras a function of wavelength, symbol L (l). (2) for a radiomet-ric quantity, indic
13、ates the concentration of the quantity per unitwavelength or frequency, indicated by the subscript lambda, asLl=dLdl , at a specific wavelength. The wavelength at whichthe spectral concentration is evaluated may be indicated by thewavelength in parentheses following the symbol, Ll(350 nm).1These tes
14、t methods are under the jurisdiction of ASTM Committee E44 onSolar, Geothermal and Other Alternative Energy Sources and is the direct respon-sibility of Subcommittee E44.05 on Solar Heating and Cooling Systems andMaterials.Current edition approved March 1, 2007. Published July 2007. Originallyapprov
15、ed in 1983. Last previous edition approved in 2002 as E 972 96 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM
16、 website.3Available from Commission Internationale de lEclairage (International Com-mission on Illumination), Barean Central de la CIE, 4 Av. du Recteur Poincar,75-Paris, France.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.8 t
17、ransmittance, t = Ft/Fi, nthe ratio of the transmit-ted flux to the incident radiant flux.4. Summary of Test Method4.1 Using sunlight as the source and a photometer as thedetector, the specimen is made to be the cover of an enclosurewith the plane of the specimen normal to the direct componentof the
18、 incident solar radiation. Luminous transmittance ismeasured as the ratio of the transmitted illuminance to theincident illuminance.5. Significance and Use5.1 Glazed apertures in buildings are generally utilized forthe controlled admission of both light and solar radiant heatenergy into the structur
19、e. Other devices may also be used toreflect light and solar radiant heat into a building.5.2 The bulk of the solar radiant energy entering a buildingin this manner possesses wavelengths that lie from 300 to 2500nm (3000 to 25 000 ). Only the portion from 380 to 760 nm(3800 to 7600 ) is visible radia
20、tion, however. In daylightingapplications, it is therefore important to distinguish the radiant(solar radiant energy) transmittance or reflectance of thesematerials from their luminous (light) transmittance or reflec-tance.5.3 For comparisons of the energy and illumination perfor-mances of building
21、fenestration systems it is important that thecalculation or measurement, or both, of solar radiant andluminous transmittance and reflectance of materials used infenestration systems use the same incident solar spectraldistribution.5.4 Solar luminous transmittance and reflectance are impor-tant prope
22、rties in describing the performance of components ofsolar illumination systems including windows, clerestories,skylights, shading and reflecting devices, and other passivefenestrations that permit the passage of daylight as well as solarradiant heat energy into buildings.5.5 This test method is usef
23、ul for determining the solarluminous transmittance and reflectance of optically inhomoge-neous sheet materials and diffusely reflecting materials used innatural lighting systems that are used alone or in conjunctionwith passive or active solar heating systems, or both. This testmethod provides a mea
24、ns of measuring solar luminous trans-mittance under fixed conditions of incidence and viewing. Thistest method has been found practical for both transparent andtranslucent materials as well as for those with transmittancesreduced by reflective coatings. This test method is particularlyapplicable to
25、the measurement of luminous transmittance ofinhomogeneous, fiber reinforced, patterned, corrugated, orotherwise optically inhomogeneous materials when the trans-mittance is averaged over an area that is large in comparison tothe inhomogeneities.6. Apparatus6.1 The apparatus to be used in this test m
26、ethod shall be asdescribed in either Test Method E 1175 or E 1084, with theexception that the sensing element shall be replaced by thesensing element described by this test method.6.1.1 The sensing element of this instrument shall be aphotometer (illuminance meter) consisting of a suitable radia-tio
27、n detector (such as a silicon photovoltaic device), a filter,and a diffusing element. The filter shall be designed so that thespectral response of the photometer very closely matches thatof the standard human observer, as specified by the C.I.E.photopic spectral luminous efficiency function tabulate
28、d inAnnex A1. The response of the photometer at wavelength l,divided by its response at 555 nm (5550 ), shall depart fromthe spectral luminous efficiency of the standard human ob-server at wavelength l by no more than 2 % for all wave-lengths from 390 to 750 nm (3900 to 7500 ). Photometerresponse sh
29、all be essentially zero outside this range.6.1.2 Cosine Response4The response of the photometer touniform, collimated incident radiation at an angle u of inci-dence, divided by its response at normal incidence (u = 0),shall depart from the cosine of u by no more than (u418) %,with u in deg.6.1.3 The
30、 diffusing element and detector electronics shall bedesigned so that the voltage (or current) output of the sensor isproportional to hemispherical illuminance incident upon it. Thephotometer shall be located inside the box so that its entranceaperture (the diffusing element) is centered approximatel
31、y 50mm (2 in.) below the plane of the rim of the box. Otherinstructions shall be closely followed.7. Test Specimens7.1 The test specimens shall be as described in Test MethodE 1175 (or Test Method E 1084).8. Procedure8.1 The tests shall be conducted in accordance with theprocedure provided in Test M
32、ethod E 1175 (or Test MethodE 1084).9. Report9.1 The report shall be prepared in accordance with TestMethod E 1175 (or Test Method E 1084) with the exceptionthat the calculated solar luminous transmittance shall bereported to the nearest 0.01 instead of solar (radiant) transmit-tance and solar illum
33、inance shall be reported instead of solarirradiance.10. Keywords10.1 photometer; sheet materials; solar luminous transmit-tance; solar photometric transmittance; sunlight; transmittance4Photometers containing so-called cosine-response diffusing attachments areavailable from: Photo Research (Division
34、 of Kollmorgan Corp.) Burbank, CA;International Light, Inc., Newburyport, MA; Optronics Laboratories, Orlando, FL;Tektronix, Beaverton, OR; and Gamma Scientific, Inc., San Diego, CA, and havebeen found satisfactory for this purpose. Other photometers may be acceptable.E 972 96 (2007)2ANNEX(Mandatory
35、 Information)A1. CIE PHOTOPIC SPECTRAL LUMINOUS EFFICIENCY Vl AND THE LUMINOUS EFFICACY CONSTANT KmA1.1 Values for the spectral luminous efficiency function Vl for photopic vision as adopted by the International Commis-sion on Illumination in 1924 and by the International Commit-tee for Weights and
36、Measures in 1933 (column for standardvalues) and intermediate interpolated values (other columns)are given in Table A1.1.NOTE A1.1The International Committee for Weights and Measures,meeting at the International Bureau of Weights and Measures near Paris,France, on Sept. 2022, 1977, approved the valu
37、e of 683 lm/W for spectralluminous efficacy constant, Km. This constant is for monochromaticradiation of a wavelength of 555 nm (5550 ) (where Vlhas its maximumvalue of 1.0002) in standard air for photopic vision.TABLE A1.1 Photopic Spectral Luminous Efficiency, V (l) (Unity at Wavelength of Maximum
38、 Luminous Efficacy)AWavelength,nmStandardValuesValues Interpolated at Intervals of 1 nm123456789380 0.00004 0.000045 0.000049 0.000054 0.000059 0.000064 0.000071 0.000080 0.000090 0.000104390 0.00012 0.000138 0.000155 0.000173 0.000193 0.000215 0.000241 0.000272 0.000308 0.000350400 0.0004 0.00045 0
39、.00049 0.00054 0.00059 0.00064 0.00071 0.00080 0.00090 0.00104410 0.0012 0.00138 0.00156 0.00174 0.00195 0.00218 0.00244 0.00274 0.00310 0.00352420 0.0040 0.00455 0.00515 0.00581 0.00651 0.00726 0.00806 0.00889 0.00976 0.01066430 0.0116 0.01257 0.01358 0.01463 0.01571 0.01684 0.01800 0.01920 0.02043
40、 0.02170440 0.023 0.0243 0.0257 0.0270 0.0284 0.0298 0.0313 0.0329 0.0345 0.0362450 0.038 0.0399 0.0418 0.0438 0.0459 0.0480 0.0502 0.0525 0.0549 0.0574460 0.060 0.0627 0.0654 0.0681 0.0709 0.0739 0.0769 0.0802 0.0836 0.0872470 0.091 0.0950 0.0992 0.1035 0.1080 0.1126 0.1175 0.1225 0.1278 0.1333480
41、0.139 0.1448 0.1507 0.1567 0.1629 0.1693 0.1761 0.1833 0.1909 0.1991490 0.208 0.2173 0.2270 0.2371 0.2476 0.2586 0.2701 0.2823 0.2951 0.3087500 0.323 0.3382 0.3544 0.3714 0.3890 0.4073 0.4259 0.4450 0.4642 0.4836510 0.503 0.5229 0.5436 0.5648 0.5865 0.6082 0.6299 0.6511 0.6717 0.6914520 0.710 0.7277
42、 0.7449 0.7615 0.7776 0.7932 0.8082 0.8225 0.8363 0.8495530 0.862 0.8739 0.8851 0.8956 0.9056 0.9149 0.9238 0.9320 0.9398 0.9471540 0.954 0.9604 0.9661 0.9713 0.9760 0.9803 0.9840 0.9873 0.9902 0.9928550 0.995 0.9969 0.9983 0.9994 1.0000 1.0002 1.0001 0.9995 0.9984 0.9969560 0.995 0.9926 0.9898 0.98
43、65 0.9828 0.9786 0.9741 0.9691 0.9638 0.9581570 0.952 0.9455 0.9386 0.9312 0.9235 0.9154 0.9069 0.8981 0.8890 0.8796580 0.870 0.8600 0.8496 0.8388 0.8277 0.8163 0.8046 0.7928 0.7809 0.7690590 0.757 0.7449 0.7327 0.7202 0.7076 0.6949 0.6822 0.6694 0.6565 0.6437600 0.631 0.6182 0.6054 0.5926 0.5797 0.
44、5668 0.5539 0.5410 0.5282 0.5156610 0.503 0.4905 0.4781 0.4658 0.4535 0.4412 0.4291 0.4170 0.4049 0.3929620 0.381 0.3690 0.3570 0.3449 0.3329 0.3210 0.3092 0.2977 0.2864 0.2755630 0.265 0.2548 0.2450 0.2354 0.2261 0.2170 0.2082 0.1996 0.1912 0.1830640 0.175 0.1672 0.1596 0.1523 0.1452 0.1382 0.1316
45、0.1251 0.1188 0.1128650 0.107 0.1014 0.0961 0.0910 0.0862 0.0816 0.0771 0.0729 0.0688 0.0648660 0.061 0.0574 0.0539 0.0506 0.0475 0.0446 0.0418 0.0391 0.0366 0.0343670 0.032 0.0299 0.0280 0.0263 0.0247 0.0232 0.0219 0.0206 0.0194 0.0182680 0.017 0.01585 0.01477 0.01376 0.01281 0.01192 0.01108 0.0103
46、0 0.00956 0.00886690 0.0082 0.00759 0.00705 0.00656 0.00612 0.00572 0.00536 0.00503 0.00471 0.00440700 0.0041 0.00381 0.00355 0.00332 0.00310 0.00291 0.00273 0.00256 0.00241 0.00225710 0.0021 0.001954 0.001821 0.001699 0.001587 0.001483 0.001387 0.001297 0.001212 0.001130720 0.00105 0.000975 0.00090
47、7 0.000845 0.000788 0.000736 0.000688 0.000644 0.000601 0.000560730 0.00052 0.000482 0.000447 0.000415 0.000387 0.000360 0.000335 0.000313 0.000291 0.000270740 0.00025 0.000231 0.000214 0.000198 0.000185 0.000172 0.000160 0.000149 0.000139 0.000130750 0.00012 0.000111 0.000103 0.000096 0.000090 0.00
48、0084 0.000078 0.000074 0.000069 0.000064760 0.00006 0.000056 0.000052 0.000048 0.000045 0.000042 0.000039 0.000037 0.000035 0.000032AIES Lighting Handbook, 1981 Reference Volume, Illuminating Engineering Society of North America, 345 East 47th Street, New York, NY 10017, Figs. 37, pp. 35.E 972 96 (2
49、007)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revisio
