1、Designation: E1477 98a (Reapproved 2013)Standard Test Method forLuminous Reflectance Factor of Acoustical Materials by Useof Integrating-Sphere Reflectometers1This standard is issued under the fixed designation E1477; the number immediately following the designation indicates the year oforiginal ado
2、ption or, in the case of revision, 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 the lumi-nous reflectance fa
3、ctor of acoustical materials for use inpredicting the levels of room illumination.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and d
4、etermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E284 Terminology of AppearanceE308 Practice for Computing the Colors of Objects by Usingthe CIE SystemE1164 Practice for Obtaining Spectrometric Data for Object-Color EvaluationE1264 Classif
5、ication for Acoustical Ceiling ProductsE1331 Test Method for Reflectance Factor and Color bySpectrophotometry Using Hemispherical GeometryE1345 Practice for Reducing the Effect of Variability ofColor Measurement by Use of Multiple MeasurementsE1347 Test Method for Color and Color-Difference Mea-sure
6、ment by Tristimulus Colorimetry3. Terminology3.1 Definitions:3.1.1 Definitions of appearance terms in Terminology E284are applicable to this test method.3.1.2 integrating sphere, nan optical device used either tocollect flux reflected or transmitted from a specimen into ahemisphere or to provide iso
7、tropic irradiation of a specimenfrom a complete hemisphere, consisting of an approximatelyspherical cavity with apertures (ports) for admitting anddetecting flux, and usually having additional apertures overwhich sample and reference specimens are placed and forincluding or excluding the specularly
8、reflected components.(E284)3.1.3 luminous, adjweighted according to the spectralluminous efficiency function V() of the CIE. (E284)3.1.4 reflectance factor, R, nratio of the flux reflected fromthe specimen to the flux reflected from the perfect reflectingdiffuser under the same geometric and spectra
9、l conditions ofmeasurement. (E284)3.1.5 perfect reflecting diffuserideal reflecting surface thatneither absorbs nor transmits light, but reflects light in adiffused manner with the radiance of the reflecting surfacebeing the same for all reflecting angles, regardless of theangular distribution of th
10、e incident light. (E284)4. Summary of Test Method4.1 Test specimens are measured for (total) luminous reflec-tance factor by standard color-measurement techniques using aspectrophotometer, tristimulus (filter) colorimeter, or otherreflectometer having a hemispherical optical measuringsystem, such as
11、 an integrating sphere. The specular componentis included to provide the total reflectance factor condition. Theinstrument standard is referenced to the perfect reflectingdiffuser. Luminous reflectance factor is calculated as CIEtristimulus value Y for the CIE 1964 (10) standard observerand CIE stan
12、dard illuminant D65 (daylight) or F2 (cool whitefluorescent).5. Significance and Use5.1 Acoustical materials are often used as the entire ceilingof rooms and are therefore an important component of thelighting system. The luminous reflectance of all importantcomponents must be known in order to pred
13、ict the level ofillumination that will be obtained.5.2 The reflecting properties of a surface are measuredrelative to those of a standard reflector, the perfect reflectingdiffuser, to provide a reflectance factor. The luminous reflec-tance factor is calculated for a standard illuminant, and a1This t
14、est method is under the jurisdiction of ASTM Committee E12 on Colorand Appearance and is the direct responsibility of Subcommittee E12.02 onSpectrophotometry and Colorimetry.Current edition approved May 1, 2013. Published May 2013. Originallyapproved in 1992. Last previous edition approved in 2008 a
15、s E1477 98a (2008).DOI: 10.1520/E1477-98AR13.2For 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.Copyright ASTM I
16、nternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1standard observer, for the standard hemispherical (integrating-sphere) geometry of illumination and viewing, in which allreflected radiation from an area of the surface is collected. Inthis way the refl
17、ecting properties of an acoustical material canbe represented by a single number measured and calculatedunder standard conditions.5.3 Acoustical materials generally have a non-glossy whiteor near-white finish. The types of surface cover a wide rangefrom smooth to deeply fissured. Measurement with in
18、tegrating-sphere reflectometers has been satisfactory although multiplemeasurements may be required to sample the surface ad-equately. Instruments with other types of optical measuringsystems may be used if it can be demonstrated that theyprovide equivalent results.5.4 The use of this test method fo
19、r determining the luminousreflectance factor is required by Classification E1264.6. Apparatus6.1 ReflectometerAny spectrophotometer, tristimulus (fil-ter) colorimeter, or other reflectometer having a hemisphericaloptical measuring system and allowing the measurement orcalculation of CIE 1964 (10) tr
20、istimulus value Y or standardilluminant D65 or F2 may be used. The instrument standardshall be calibrated to provide absolute reflectance factorsrelative to the perfect reflecting diffuser. For this test method,the perfect reflecting diffuser shall be assigned a reflectancefactor of 100.00.7. Proced
21、ure7.1 Standardize and operate the instrument in accordancewith Practice E1164 and either Test Method E1331 or TestMethod E1347, whichever is applicable. Make the measure-ments with the specular component included.7.2 Most reflectometers compute the luminous reflectancefactor automatically; select p
22、arameters to obtain CIE Y for the1964 (10) standard observer and standard illuminant D65 orF2. If the computation is not automatic, calculate Y inaccordance with Practice E308.7.3 Operate the reflectometer with the largest available areaof illumination or view. Measure at least three test specimensr
23、andomly selected from the tiles or panels constituting eachsample.7.4 Additional test specimens or multiple measurements ofeach test specimen may be required to meet the tentativetolerance of 60.1 unit of Y. Compute the number of testspecimens or of multiple measurements in accordance withPractice E
24、1345.NOTE 1Drilled acoustical materials, which have large diameter holesof appreciable depth, have a high reflectance from the tile surface and alow reflectance from the hole location. Fissured tiles provide a similar butless exaggerated condition. In addition, fissured tiles and striated tiles have
25、reflectances that depend on the angle of incidence of the light relative tothe general direction of the surface features. This test method provides asuitable average over these surface features.8. Report8.1 Report the following information:8.1.1 The material or sample identification,8.1.2 The instru
26、ment used, and any pertinent informationconcerning its standardization and operation,8.1.3 The number of test specimens measured and thenumber of multiple measurements of each test specimen, and8.1.4 The average luminous reflectance factor for the mate-rial tested and the CIE illuminant used.9. Prec
27、ision and Bias9.1 RepeatabilityMeasurement data obtained show thatrepeatability of test equipment is on the order of 0.2 unit for theY CIE function of the CIE 10 Observer and Illuminant D65.9.2 ReproducibilityThe reproducibility within a labora-tory is on the order of 0.4 unit for the Y CIE function
28、 of the CIE10 Observer and Illuminant D65. This value includes operatorreproducibility, test equipment repeatability, and nominalsample variation.9.3 Each user should evaluate the precision and bias of hisinstrument by routinely measuring typical specimens, and thendeciding whether the resulting unc
29、ertainties are sufficientlysmall for the purpose for which the data are being obtained.10. Keywords10.1 acoustical materials; integrating sphere; luminous re-flectance factor; reflectometerASTM International takes no position respecting the validity of any patent rights asserted in connection with a
30、ny 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 technica
31、l committee 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
32、at a 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
33、 Drive, 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.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E1477 98a (2013)2
