1、Designation: E972 96 (Reapproved 2013)Standard Test Method forSolar Photometric Transmittance of Sheet Materials UsingSunlight1This standard is issued under the fixed designation E972; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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. So
3、larphotometric 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 E1175 (or Test Method E1084).1.2 The purpose of this test method is to specify a photo-metric sen
4、sor 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 user of
5、 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:2E772 Terminology of Solar Energy ConversionE1084 Test Method for Solar Transmittance (Terrestrial) ofSheet Materials
6、 Using SunlightE1175 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 method, refer to Te
7、rminology E772.3.1.1 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 the weightingfunc
8、tion.3.1.3 radiant flux, = d Q/dtWatt (W), n poweremitted, transferred, or received in the form of electromagneticwaves or photons. See radiometric properties and quantities.3.1.4 reflectance, , r/i,nthe ratio of the reflected fluxto the incident flux.3.1.5 solar irradiance at a point of a surface,
9、Es=d/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 ofincidence and of transmissi
10、on 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) referring to a radiometric term,
11、 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 Esused as the weighting function.3.1.7 spectral, adj(1) for dimensionless op
12、ticalproperties, indicates that the property was evaluated at aspecific wavelength, , within a small wavelength interval, about , symbol wavelength in parentheses, as L (350 nm, 3500), or as a function of wavelength, symbol L(). (2) for aradiometric quantity, indicates the concentration of the quan-
13、tity per unit wavelength or frequency, indicated by the sub-script lambda, as L=dLd, at a specific wavelength. Thewavelength at which the spectral concentration is evaluatedmay be indicated by the wavelength in parentheses followingthe symbol, L(350 nm).1These test methods are under the jurisdiction
14、 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 Nov. 1, 2013. Published December 2013. Originallyapproved in 1983. Last previous edition
15、 approved in 2007 as E972 96 (2007).DOI: 10.1520/E0972-96R13.2For 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 website.
16、3Available from Commission Internationale de lEclairage (International Com-mission on Illumination), Barean Central de la CIE, 4 Av. du Recteur Poincar,75-Paris, France.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.8 transmittan
17、ce, = t/i,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 incident solar
18、 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 structure. Other device
19、s 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 radiation, however.
20、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 fenestration sy
21、stems 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 properties in descri
22、bing 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 useful for determin
23、ing 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 means of measuring
24、 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 the measurement
25、 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 method shall be
26、asdescribed in either Test Method E1175 or E1084, 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-tion detector (such
27、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 tabulated inAnnex A1. The
28、 response of the photometer at wavelength ,divided by its response at 555 nm (5550 ), shall depart fromthe spectral luminous efficiency of the standard human ob-server at wavelength by no more than 2 % for all wavelengthsfrom 390 to 750 nm (3900 to 7500 ). Photometer responseshall be essentially zer
29、o outside this range.6.1.2 Cosine Response4The response of the photometer touniform, collimated incident radiation at an angle ofincidence, divided by its response at normal incidence ( = 0),shall depart from the cosine of by no more than ( 18) %,with in deg.6.1.3 The diffusing element and detector
30、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 approximately 50mm (2 in.) below the plane o
31、f the rim of the box. Otherinstructions shall be closely followed.7. Test Specimens7.1 The test specimens shall be as described in Test MethodE1175 (or Test Method E1084).8. Procedure8.1 The tests shall be conducted in accordance with theprocedure provided in Test Method E1175 (or Test MethodE1084).
32、9. Report9.1 The report shall be prepared in accordance with TestMethod E1175 (or Test Method E1084) with the exception thatthe calculated solar luminous transmittance shall be reported tothe nearest 0.01 instead of solar (radiant) transmittance andsolar illuminance shall be reported instead of sola
33、r irradiance.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 of Kollmorgan Corp.) Burbank, CA;Inter
34、national 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.E972 96 (2013)2ANNEX(Mandatory Information)A1. CIE PHOTOPIC SPECTRAL L
35、UMINOUS EFFICIENCY V AND THE LUMINOUS EFFICACY CONSTANT KmA1.1 Values for the spectral luminous efficiency function Vfor photopic vision as adopted by the International Commis-sion on Illumination in 1924 and by the International Commit-tee for Weights and Measures in 1933 (column for standardvalues
36、) 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 value of 683 lm/W for spectralluminous efficacy
37、 constant, Km. This constant is for monochromaticradiation of a wavelength of 555 nm (5550 ) (where Vhas its maximumvalue of 1.0002) in standard air for photopic vision.E972 96 (2013)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any it
38、em 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 com
39、mittee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a
40、meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Driv
41、e, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.or
42、g). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE A1.1 Photopic Spectral Luminous Efficiency, V() (Unity at Wavelength of Maximum Luminous Efficacy)AWavelength,nmStandardValuesValues Interpolated at Intervals of 1 nm123456789380
43、 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 0.00049 0.00054 0.00059 0.00064 0.00071 0.00080 0.00090 0.00104410 0.0012 0.00138 0.00156 0.00174 0.
44、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 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.
45、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 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
46、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 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 0.914
47、9 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 0.9865 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 0.8
48、981 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 0.5668 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
49、.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 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 0.01030 0.00956 0.00886690 0.0
